xref: /linux/drivers/ata/libata-eh.c (revision ce7240e445303de3ca66e6d08f17a2ec278a5bf6)
1 /*
2  *  libata-eh.c - libata error handling
3  *
4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2006 Tejun Heo <htejun@gmail.com>
9  *
10  *
11  *  This program is free software; you can redistribute it and/or
12  *  modify it under the terms of the GNU General Public License as
13  *  published by the Free Software Foundation; either version 2, or
14  *  (at your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License
22  *  along with this program; see the file COPYING.  If not, write to
23  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
24  *  USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/blkdev.h>
37 #include <linux/export.h>
38 #include <linux/pci.h>
39 #include <scsi/scsi.h>
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi_eh.h>
42 #include <scsi/scsi_device.h>
43 #include <scsi/scsi_cmnd.h>
44 #include <scsi/scsi_dbg.h>
45 #include "../scsi/scsi_transport_api.h"
46 
47 #include <linux/libata.h>
48 
49 #include "libata.h"
50 
51 enum {
52 	/* speed down verdicts */
53 	ATA_EH_SPDN_NCQ_OFF		= (1 << 0),
54 	ATA_EH_SPDN_SPEED_DOWN		= (1 << 1),
55 	ATA_EH_SPDN_FALLBACK_TO_PIO	= (1 << 2),
56 	ATA_EH_SPDN_KEEP_ERRORS		= (1 << 3),
57 
58 	/* error flags */
59 	ATA_EFLAG_IS_IO			= (1 << 0),
60 	ATA_EFLAG_DUBIOUS_XFER		= (1 << 1),
61 	ATA_EFLAG_OLD_ER                = (1 << 31),
62 
63 	/* error categories */
64 	ATA_ECAT_NONE			= 0,
65 	ATA_ECAT_ATA_BUS		= 1,
66 	ATA_ECAT_TOUT_HSM		= 2,
67 	ATA_ECAT_UNK_DEV		= 3,
68 	ATA_ECAT_DUBIOUS_NONE		= 4,
69 	ATA_ECAT_DUBIOUS_ATA_BUS	= 5,
70 	ATA_ECAT_DUBIOUS_TOUT_HSM	= 6,
71 	ATA_ECAT_DUBIOUS_UNK_DEV	= 7,
72 	ATA_ECAT_NR			= 8,
73 
74 	ATA_EH_CMD_DFL_TIMEOUT		=  5000,
75 
76 	/* always put at least this amount of time between resets */
77 	ATA_EH_RESET_COOL_DOWN		=  5000,
78 
79 	/* Waiting in ->prereset can never be reliable.  It's
80 	 * sometimes nice to wait there but it can't be depended upon;
81 	 * otherwise, we wouldn't be resetting.  Just give it enough
82 	 * time for most drives to spin up.
83 	 */
84 	ATA_EH_PRERESET_TIMEOUT		= 10000,
85 	ATA_EH_FASTDRAIN_INTERVAL	=  3000,
86 
87 	ATA_EH_UA_TRIES			= 5,
88 
89 	/* probe speed down parameters, see ata_eh_schedule_probe() */
90 	ATA_EH_PROBE_TRIAL_INTERVAL	= 60000,	/* 1 min */
91 	ATA_EH_PROBE_TRIALS		= 2,
92 };
93 
94 /* The following table determines how we sequence resets.  Each entry
95  * represents timeout for that try.  The first try can be soft or
96  * hardreset.  All others are hardreset if available.  In most cases
97  * the first reset w/ 10sec timeout should succeed.  Following entries
98  * are mostly for error handling, hotplug and retarded devices.
99  */
100 static const unsigned long ata_eh_reset_timeouts[] = {
101 	10000,	/* most drives spin up by 10sec */
102 	10000,	/* > 99% working drives spin up before 20sec */
103 	35000,	/* give > 30 secs of idleness for retarded devices */
104 	 5000,	/* and sweet one last chance */
105 	ULONG_MAX, /* > 1 min has elapsed, give up */
106 };
107 
108 static const unsigned long ata_eh_identify_timeouts[] = {
109 	 5000,	/* covers > 99% of successes and not too boring on failures */
110 	10000,  /* combined time till here is enough even for media access */
111 	30000,	/* for true idiots */
112 	ULONG_MAX,
113 };
114 
115 static const unsigned long ata_eh_flush_timeouts[] = {
116 	15000,	/* be generous with flush */
117 	15000,  /* ditto */
118 	30000,	/* and even more generous */
119 	ULONG_MAX,
120 };
121 
122 static const unsigned long ata_eh_other_timeouts[] = {
123 	 5000,	/* same rationale as identify timeout */
124 	10000,	/* ditto */
125 	/* but no merciful 30sec for other commands, it just isn't worth it */
126 	ULONG_MAX,
127 };
128 
129 struct ata_eh_cmd_timeout_ent {
130 	const u8		*commands;
131 	const unsigned long	*timeouts;
132 };
133 
134 /* The following table determines timeouts to use for EH internal
135  * commands.  Each table entry is a command class and matches the
136  * commands the entry applies to and the timeout table to use.
137  *
138  * On the retry after a command timed out, the next timeout value from
139  * the table is used.  If the table doesn't contain further entries,
140  * the last value is used.
141  *
142  * ehc->cmd_timeout_idx keeps track of which timeout to use per
143  * command class, so if SET_FEATURES times out on the first try, the
144  * next try will use the second timeout value only for that class.
145  */
146 #define CMDS(cmds...)	(const u8 []){ cmds, 0 }
147 static const struct ata_eh_cmd_timeout_ent
148 ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
149 	{ .commands = CMDS(ATA_CMD_ID_ATA, ATA_CMD_ID_ATAPI),
150 	  .timeouts = ata_eh_identify_timeouts, },
151 	{ .commands = CMDS(ATA_CMD_READ_NATIVE_MAX, ATA_CMD_READ_NATIVE_MAX_EXT),
152 	  .timeouts = ata_eh_other_timeouts, },
153 	{ .commands = CMDS(ATA_CMD_SET_MAX, ATA_CMD_SET_MAX_EXT),
154 	  .timeouts = ata_eh_other_timeouts, },
155 	{ .commands = CMDS(ATA_CMD_SET_FEATURES),
156 	  .timeouts = ata_eh_other_timeouts, },
157 	{ .commands = CMDS(ATA_CMD_INIT_DEV_PARAMS),
158 	  .timeouts = ata_eh_other_timeouts, },
159 	{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
160 	  .timeouts = ata_eh_flush_timeouts },
161 };
162 #undef CMDS
163 
164 static void __ata_port_freeze(struct ata_port *ap);
165 #ifdef CONFIG_PM
166 static void ata_eh_handle_port_suspend(struct ata_port *ap);
167 static void ata_eh_handle_port_resume(struct ata_port *ap);
168 #else /* CONFIG_PM */
169 static void ata_eh_handle_port_suspend(struct ata_port *ap)
170 { }
171 
172 static void ata_eh_handle_port_resume(struct ata_port *ap)
173 { }
174 #endif /* CONFIG_PM */
175 
176 static void __ata_ehi_pushv_desc(struct ata_eh_info *ehi, const char *fmt,
177 				 va_list args)
178 {
179 	ehi->desc_len += vscnprintf(ehi->desc + ehi->desc_len,
180 				     ATA_EH_DESC_LEN - ehi->desc_len,
181 				     fmt, args);
182 }
183 
184 /**
185  *	__ata_ehi_push_desc - push error description without adding separator
186  *	@ehi: target EHI
187  *	@fmt: printf format string
188  *
189  *	Format string according to @fmt and append it to @ehi->desc.
190  *
191  *	LOCKING:
192  *	spin_lock_irqsave(host lock)
193  */
194 void __ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
195 {
196 	va_list args;
197 
198 	va_start(args, fmt);
199 	__ata_ehi_pushv_desc(ehi, fmt, args);
200 	va_end(args);
201 }
202 
203 /**
204  *	ata_ehi_push_desc - push error description with separator
205  *	@ehi: target EHI
206  *	@fmt: printf format string
207  *
208  *	Format string according to @fmt and append it to @ehi->desc.
209  *	If @ehi->desc is not empty, ", " is added in-between.
210  *
211  *	LOCKING:
212  *	spin_lock_irqsave(host lock)
213  */
214 void ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
215 {
216 	va_list args;
217 
218 	if (ehi->desc_len)
219 		__ata_ehi_push_desc(ehi, ", ");
220 
221 	va_start(args, fmt);
222 	__ata_ehi_pushv_desc(ehi, fmt, args);
223 	va_end(args);
224 }
225 
226 /**
227  *	ata_ehi_clear_desc - clean error description
228  *	@ehi: target EHI
229  *
230  *	Clear @ehi->desc.
231  *
232  *	LOCKING:
233  *	spin_lock_irqsave(host lock)
234  */
235 void ata_ehi_clear_desc(struct ata_eh_info *ehi)
236 {
237 	ehi->desc[0] = '\0';
238 	ehi->desc_len = 0;
239 }
240 
241 /**
242  *	ata_port_desc - append port description
243  *	@ap: target ATA port
244  *	@fmt: printf format string
245  *
246  *	Format string according to @fmt and append it to port
247  *	description.  If port description is not empty, " " is added
248  *	in-between.  This function is to be used while initializing
249  *	ata_host.  The description is printed on host registration.
250  *
251  *	LOCKING:
252  *	None.
253  */
254 void ata_port_desc(struct ata_port *ap, const char *fmt, ...)
255 {
256 	va_list args;
257 
258 	WARN_ON(!(ap->pflags & ATA_PFLAG_INITIALIZING));
259 
260 	if (ap->link.eh_info.desc_len)
261 		__ata_ehi_push_desc(&ap->link.eh_info, " ");
262 
263 	va_start(args, fmt);
264 	__ata_ehi_pushv_desc(&ap->link.eh_info, fmt, args);
265 	va_end(args);
266 }
267 
268 #ifdef CONFIG_PCI
269 
270 /**
271  *	ata_port_pbar_desc - append PCI BAR description
272  *	@ap: target ATA port
273  *	@bar: target PCI BAR
274  *	@offset: offset into PCI BAR
275  *	@name: name of the area
276  *
277  *	If @offset is negative, this function formats a string which
278  *	contains the name, address, size and type of the BAR and
279  *	appends it to the port description.  If @offset is zero or
280  *	positive, only name and offsetted address is appended.
281  *
282  *	LOCKING:
283  *	None.
284  */
285 void ata_port_pbar_desc(struct ata_port *ap, int bar, ssize_t offset,
286 			const char *name)
287 {
288 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
289 	char *type = "";
290 	unsigned long long start, len;
291 
292 	if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
293 		type = "m";
294 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
295 		type = "i";
296 
297 	start = (unsigned long long)pci_resource_start(pdev, bar);
298 	len = (unsigned long long)pci_resource_len(pdev, bar);
299 
300 	if (offset < 0)
301 		ata_port_desc(ap, "%s %s%llu@0x%llx", name, type, len, start);
302 	else
303 		ata_port_desc(ap, "%s 0x%llx", name,
304 				start + (unsigned long long)offset);
305 }
306 
307 #endif /* CONFIG_PCI */
308 
309 static int ata_lookup_timeout_table(u8 cmd)
310 {
311 	int i;
312 
313 	for (i = 0; i < ATA_EH_CMD_TIMEOUT_TABLE_SIZE; i++) {
314 		const u8 *cur;
315 
316 		for (cur = ata_eh_cmd_timeout_table[i].commands; *cur; cur++)
317 			if (*cur == cmd)
318 				return i;
319 	}
320 
321 	return -1;
322 }
323 
324 /**
325  *	ata_internal_cmd_timeout - determine timeout for an internal command
326  *	@dev: target device
327  *	@cmd: internal command to be issued
328  *
329  *	Determine timeout for internal command @cmd for @dev.
330  *
331  *	LOCKING:
332  *	EH context.
333  *
334  *	RETURNS:
335  *	Determined timeout.
336  */
337 unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd)
338 {
339 	struct ata_eh_context *ehc = &dev->link->eh_context;
340 	int ent = ata_lookup_timeout_table(cmd);
341 	int idx;
342 
343 	if (ent < 0)
344 		return ATA_EH_CMD_DFL_TIMEOUT;
345 
346 	idx = ehc->cmd_timeout_idx[dev->devno][ent];
347 	return ata_eh_cmd_timeout_table[ent].timeouts[idx];
348 }
349 
350 /**
351  *	ata_internal_cmd_timed_out - notification for internal command timeout
352  *	@dev: target device
353  *	@cmd: internal command which timed out
354  *
355  *	Notify EH that internal command @cmd for @dev timed out.  This
356  *	function should be called only for commands whose timeouts are
357  *	determined using ata_internal_cmd_timeout().
358  *
359  *	LOCKING:
360  *	EH context.
361  */
362 void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd)
363 {
364 	struct ata_eh_context *ehc = &dev->link->eh_context;
365 	int ent = ata_lookup_timeout_table(cmd);
366 	int idx;
367 
368 	if (ent < 0)
369 		return;
370 
371 	idx = ehc->cmd_timeout_idx[dev->devno][ent];
372 	if (ata_eh_cmd_timeout_table[ent].timeouts[idx + 1] != ULONG_MAX)
373 		ehc->cmd_timeout_idx[dev->devno][ent]++;
374 }
375 
376 static void ata_ering_record(struct ata_ering *ering, unsigned int eflags,
377 			     unsigned int err_mask)
378 {
379 	struct ata_ering_entry *ent;
380 
381 	WARN_ON(!err_mask);
382 
383 	ering->cursor++;
384 	ering->cursor %= ATA_ERING_SIZE;
385 
386 	ent = &ering->ring[ering->cursor];
387 	ent->eflags = eflags;
388 	ent->err_mask = err_mask;
389 	ent->timestamp = get_jiffies_64();
390 }
391 
392 static struct ata_ering_entry *ata_ering_top(struct ata_ering *ering)
393 {
394 	struct ata_ering_entry *ent = &ering->ring[ering->cursor];
395 
396 	if (ent->err_mask)
397 		return ent;
398 	return NULL;
399 }
400 
401 int ata_ering_map(struct ata_ering *ering,
402 		  int (*map_fn)(struct ata_ering_entry *, void *),
403 		  void *arg)
404 {
405 	int idx, rc = 0;
406 	struct ata_ering_entry *ent;
407 
408 	idx = ering->cursor;
409 	do {
410 		ent = &ering->ring[idx];
411 		if (!ent->err_mask)
412 			break;
413 		rc = map_fn(ent, arg);
414 		if (rc)
415 			break;
416 		idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE;
417 	} while (idx != ering->cursor);
418 
419 	return rc;
420 }
421 
422 int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
423 {
424 	ent->eflags |= ATA_EFLAG_OLD_ER;
425 	return 0;
426 }
427 
428 static void ata_ering_clear(struct ata_ering *ering)
429 {
430 	ata_ering_map(ering, ata_ering_clear_cb, NULL);
431 }
432 
433 static unsigned int ata_eh_dev_action(struct ata_device *dev)
434 {
435 	struct ata_eh_context *ehc = &dev->link->eh_context;
436 
437 	return ehc->i.action | ehc->i.dev_action[dev->devno];
438 }
439 
440 static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
441 				struct ata_eh_info *ehi, unsigned int action)
442 {
443 	struct ata_device *tdev;
444 
445 	if (!dev) {
446 		ehi->action &= ~action;
447 		ata_for_each_dev(tdev, link, ALL)
448 			ehi->dev_action[tdev->devno] &= ~action;
449 	} else {
450 		/* doesn't make sense for port-wide EH actions */
451 		WARN_ON(!(action & ATA_EH_PERDEV_MASK));
452 
453 		/* break ehi->action into ehi->dev_action */
454 		if (ehi->action & action) {
455 			ata_for_each_dev(tdev, link, ALL)
456 				ehi->dev_action[tdev->devno] |=
457 					ehi->action & action;
458 			ehi->action &= ~action;
459 		}
460 
461 		/* turn off the specified per-dev action */
462 		ehi->dev_action[dev->devno] &= ~action;
463 	}
464 }
465 
466 /**
467  *	ata_eh_acquire - acquire EH ownership
468  *	@ap: ATA port to acquire EH ownership for
469  *
470  *	Acquire EH ownership for @ap.  This is the basic exclusion
471  *	mechanism for ports sharing a host.  Only one port hanging off
472  *	the same host can claim the ownership of EH.
473  *
474  *	LOCKING:
475  *	EH context.
476  */
477 void ata_eh_acquire(struct ata_port *ap)
478 {
479 	mutex_lock(&ap->host->eh_mutex);
480 	WARN_ON_ONCE(ap->host->eh_owner);
481 	ap->host->eh_owner = current;
482 }
483 
484 /**
485  *	ata_eh_release - release EH ownership
486  *	@ap: ATA port to release EH ownership for
487  *
488  *	Release EH ownership for @ap if the caller.  The caller must
489  *	have acquired EH ownership using ata_eh_acquire() previously.
490  *
491  *	LOCKING:
492  *	EH context.
493  */
494 void ata_eh_release(struct ata_port *ap)
495 {
496 	WARN_ON_ONCE(ap->host->eh_owner != current);
497 	ap->host->eh_owner = NULL;
498 	mutex_unlock(&ap->host->eh_mutex);
499 }
500 
501 /**
502  *	ata_scsi_timed_out - SCSI layer time out callback
503  *	@cmd: timed out SCSI command
504  *
505  *	Handles SCSI layer timeout.  We race with normal completion of
506  *	the qc for @cmd.  If the qc is already gone, we lose and let
507  *	the scsi command finish (EH_HANDLED).  Otherwise, the qc has
508  *	timed out and EH should be invoked.  Prevent ata_qc_complete()
509  *	from finishing it by setting EH_SCHEDULED and return
510  *	EH_NOT_HANDLED.
511  *
512  *	TODO: kill this function once old EH is gone.
513  *
514  *	LOCKING:
515  *	Called from timer context
516  *
517  *	RETURNS:
518  *	EH_HANDLED or EH_NOT_HANDLED
519  */
520 enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
521 {
522 	struct Scsi_Host *host = cmd->device->host;
523 	struct ata_port *ap = ata_shost_to_port(host);
524 	unsigned long flags;
525 	struct ata_queued_cmd *qc;
526 	enum blk_eh_timer_return ret;
527 
528 	DPRINTK("ENTER\n");
529 
530 	if (ap->ops->error_handler) {
531 		ret = BLK_EH_NOT_HANDLED;
532 		goto out;
533 	}
534 
535 	ret = BLK_EH_HANDLED;
536 	spin_lock_irqsave(ap->lock, flags);
537 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
538 	if (qc) {
539 		WARN_ON(qc->scsicmd != cmd);
540 		qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
541 		qc->err_mask |= AC_ERR_TIMEOUT;
542 		ret = BLK_EH_NOT_HANDLED;
543 	}
544 	spin_unlock_irqrestore(ap->lock, flags);
545 
546  out:
547 	DPRINTK("EXIT, ret=%d\n", ret);
548 	return ret;
549 }
550 
551 static void ata_eh_unload(struct ata_port *ap)
552 {
553 	struct ata_link *link;
554 	struct ata_device *dev;
555 	unsigned long flags;
556 
557 	/* Restore SControl IPM and SPD for the next driver and
558 	 * disable attached devices.
559 	 */
560 	ata_for_each_link(link, ap, PMP_FIRST) {
561 		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
562 		ata_for_each_dev(dev, link, ALL)
563 			ata_dev_disable(dev);
564 	}
565 
566 	/* freeze and set UNLOADED */
567 	spin_lock_irqsave(ap->lock, flags);
568 
569 	ata_port_freeze(ap);			/* won't be thawed */
570 	ap->pflags &= ~ATA_PFLAG_EH_PENDING;	/* clear pending from freeze */
571 	ap->pflags |= ATA_PFLAG_UNLOADED;
572 
573 	spin_unlock_irqrestore(ap->lock, flags);
574 }
575 
576 /**
577  *	ata_scsi_error - SCSI layer error handler callback
578  *	@host: SCSI host on which error occurred
579  *
580  *	Handles SCSI-layer-thrown error events.
581  *
582  *	LOCKING:
583  *	Inherited from SCSI layer (none, can sleep)
584  *
585  *	RETURNS:
586  *	Zero.
587  */
588 void ata_scsi_error(struct Scsi_Host *host)
589 {
590 	struct ata_port *ap = ata_shost_to_port(host);
591 	unsigned long flags;
592 	LIST_HEAD(eh_work_q);
593 
594 	DPRINTK("ENTER\n");
595 
596 	spin_lock_irqsave(host->host_lock, flags);
597 	list_splice_init(&host->eh_cmd_q, &eh_work_q);
598 	spin_unlock_irqrestore(host->host_lock, flags);
599 
600 	ata_scsi_cmd_error_handler(host, ap, &eh_work_q);
601 
602 	/* If we timed raced normal completion and there is nothing to
603 	   recover nr_timedout == 0 why exactly are we doing error recovery ? */
604 	ata_scsi_port_error_handler(host, ap);
605 
606 	/* finish or retry handled scmd's and clean up */
607 	WARN_ON(host->host_failed || !list_empty(&eh_work_q));
608 
609 	DPRINTK("EXIT\n");
610 }
611 
612 /**
613  * ata_scsi_cmd_error_handler - error callback for a list of commands
614  * @host:	scsi host containing the port
615  * @ap:		ATA port within the host
616  * @eh_work_q:	list of commands to process
617  *
618  * process the given list of commands and return those finished to the
619  * ap->eh_done_q.  This function is the first part of the libata error
620  * handler which processes a given list of failed commands.
621  */
622 void ata_scsi_cmd_error_handler(struct Scsi_Host *host, struct ata_port *ap,
623 				struct list_head *eh_work_q)
624 {
625 	int i;
626 	unsigned long flags;
627 
628 	/* make sure sff pio task is not running */
629 	ata_sff_flush_pio_task(ap);
630 
631 	/* synchronize with host lock and sort out timeouts */
632 
633 	/* For new EH, all qcs are finished in one of three ways -
634 	 * normal completion, error completion, and SCSI timeout.
635 	 * Both completions can race against SCSI timeout.  When normal
636 	 * completion wins, the qc never reaches EH.  When error
637 	 * completion wins, the qc has ATA_QCFLAG_FAILED set.
638 	 *
639 	 * When SCSI timeout wins, things are a bit more complex.
640 	 * Normal or error completion can occur after the timeout but
641 	 * before this point.  In such cases, both types of
642 	 * completions are honored.  A scmd is determined to have
643 	 * timed out iff its associated qc is active and not failed.
644 	 */
645 	if (ap->ops->error_handler) {
646 		struct scsi_cmnd *scmd, *tmp;
647 		int nr_timedout = 0;
648 
649 		spin_lock_irqsave(ap->lock, flags);
650 
651 		/* This must occur under the ap->lock as we don't want
652 		   a polled recovery to race the real interrupt handler
653 
654 		   The lost_interrupt handler checks for any completed but
655 		   non-notified command and completes much like an IRQ handler.
656 
657 		   We then fall into the error recovery code which will treat
658 		   this as if normal completion won the race */
659 
660 		if (ap->ops->lost_interrupt)
661 			ap->ops->lost_interrupt(ap);
662 
663 		list_for_each_entry_safe(scmd, tmp, eh_work_q, eh_entry) {
664 			struct ata_queued_cmd *qc;
665 
666 			for (i = 0; i < ATA_MAX_QUEUE; i++) {
667 				qc = __ata_qc_from_tag(ap, i);
668 				if (qc->flags & ATA_QCFLAG_ACTIVE &&
669 				    qc->scsicmd == scmd)
670 					break;
671 			}
672 
673 			if (i < ATA_MAX_QUEUE) {
674 				/* the scmd has an associated qc */
675 				if (!(qc->flags & ATA_QCFLAG_FAILED)) {
676 					/* which hasn't failed yet, timeout */
677 					qc->err_mask |= AC_ERR_TIMEOUT;
678 					qc->flags |= ATA_QCFLAG_FAILED;
679 					nr_timedout++;
680 				}
681 			} else {
682 				/* Normal completion occurred after
683 				 * SCSI timeout but before this point.
684 				 * Successfully complete it.
685 				 */
686 				scmd->retries = scmd->allowed;
687 				scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
688 			}
689 		}
690 
691 		/* If we have timed out qcs.  They belong to EH from
692 		 * this point but the state of the controller is
693 		 * unknown.  Freeze the port to make sure the IRQ
694 		 * handler doesn't diddle with those qcs.  This must
695 		 * be done atomically w.r.t. setting QCFLAG_FAILED.
696 		 */
697 		if (nr_timedout)
698 			__ata_port_freeze(ap);
699 
700 		spin_unlock_irqrestore(ap->lock, flags);
701 
702 		/* initialize eh_tries */
703 		ap->eh_tries = ATA_EH_MAX_TRIES;
704 	} else
705 		spin_unlock_wait(ap->lock);
706 
707 }
708 EXPORT_SYMBOL(ata_scsi_cmd_error_handler);
709 
710 /**
711  * ata_scsi_port_error_handler - recover the port after the commands
712  * @host:	SCSI host containing the port
713  * @ap:		the ATA port
714  *
715  * Handle the recovery of the port @ap after all the commands
716  * have been recovered.
717  */
718 void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
719 {
720 	unsigned long flags;
721 
722 	/* invoke error handler */
723 	if (ap->ops->error_handler) {
724 		struct ata_link *link;
725 
726 		/* acquire EH ownership */
727 		ata_eh_acquire(ap);
728  repeat:
729 		/* kill fast drain timer */
730 		del_timer_sync(&ap->fastdrain_timer);
731 
732 		/* process port resume request */
733 		ata_eh_handle_port_resume(ap);
734 
735 		/* fetch & clear EH info */
736 		spin_lock_irqsave(ap->lock, flags);
737 
738 		ata_for_each_link(link, ap, HOST_FIRST) {
739 			struct ata_eh_context *ehc = &link->eh_context;
740 			struct ata_device *dev;
741 
742 			memset(&link->eh_context, 0, sizeof(link->eh_context));
743 			link->eh_context.i = link->eh_info;
744 			memset(&link->eh_info, 0, sizeof(link->eh_info));
745 
746 			ata_for_each_dev(dev, link, ENABLED) {
747 				int devno = dev->devno;
748 
749 				ehc->saved_xfer_mode[devno] = dev->xfer_mode;
750 				if (ata_ncq_enabled(dev))
751 					ehc->saved_ncq_enabled |= 1 << devno;
752 			}
753 		}
754 
755 		ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
756 		ap->pflags &= ~ATA_PFLAG_EH_PENDING;
757 		ap->excl_link = NULL;	/* don't maintain exclusion over EH */
758 
759 		spin_unlock_irqrestore(ap->lock, flags);
760 
761 		/* invoke EH, skip if unloading or suspended */
762 		if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
763 			ap->ops->error_handler(ap);
764 		else {
765 			/* if unloading, commence suicide */
766 			if ((ap->pflags & ATA_PFLAG_UNLOADING) &&
767 			    !(ap->pflags & ATA_PFLAG_UNLOADED))
768 				ata_eh_unload(ap);
769 			ata_eh_finish(ap);
770 		}
771 
772 		/* process port suspend request */
773 		ata_eh_handle_port_suspend(ap);
774 
775 		/* Exception might have happened after ->error_handler
776 		 * recovered the port but before this point.  Repeat
777 		 * EH in such case.
778 		 */
779 		spin_lock_irqsave(ap->lock, flags);
780 
781 		if (ap->pflags & ATA_PFLAG_EH_PENDING) {
782 			if (--ap->eh_tries) {
783 				spin_unlock_irqrestore(ap->lock, flags);
784 				goto repeat;
785 			}
786 			ata_port_err(ap,
787 				     "EH pending after %d tries, giving up\n",
788 				     ATA_EH_MAX_TRIES);
789 			ap->pflags &= ~ATA_PFLAG_EH_PENDING;
790 		}
791 
792 		/* this run is complete, make sure EH info is clear */
793 		ata_for_each_link(link, ap, HOST_FIRST)
794 			memset(&link->eh_info, 0, sizeof(link->eh_info));
795 
796 		/* Clear host_eh_scheduled while holding ap->lock such
797 		 * that if exception occurs after this point but
798 		 * before EH completion, SCSI midlayer will
799 		 * re-initiate EH.
800 		 */
801 		host->host_eh_scheduled = 0;
802 
803 		spin_unlock_irqrestore(ap->lock, flags);
804 		ata_eh_release(ap);
805 	} else {
806 		WARN_ON(ata_qc_from_tag(ap, ap->link.active_tag) == NULL);
807 		ap->ops->eng_timeout(ap);
808 	}
809 
810 	scsi_eh_flush_done_q(&ap->eh_done_q);
811 
812 	/* clean up */
813 	spin_lock_irqsave(ap->lock, flags);
814 
815 	if (ap->pflags & ATA_PFLAG_LOADING)
816 		ap->pflags &= ~ATA_PFLAG_LOADING;
817 	else if (ap->pflags & ATA_PFLAG_SCSI_HOTPLUG)
818 		schedule_delayed_work(&ap->hotplug_task, 0);
819 
820 	if (ap->pflags & ATA_PFLAG_RECOVERED)
821 		ata_port_info(ap, "EH complete\n");
822 
823 	ap->pflags &= ~(ATA_PFLAG_SCSI_HOTPLUG | ATA_PFLAG_RECOVERED);
824 
825 	/* tell wait_eh that we're done */
826 	ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
827 	wake_up_all(&ap->eh_wait_q);
828 
829 	spin_unlock_irqrestore(ap->lock, flags);
830 }
831 EXPORT_SYMBOL_GPL(ata_scsi_port_error_handler);
832 
833 /**
834  *	ata_port_wait_eh - Wait for the currently pending EH to complete
835  *	@ap: Port to wait EH for
836  *
837  *	Wait until the currently pending EH is complete.
838  *
839  *	LOCKING:
840  *	Kernel thread context (may sleep).
841  */
842 void ata_port_wait_eh(struct ata_port *ap)
843 {
844 	unsigned long flags;
845 	DEFINE_WAIT(wait);
846 
847  retry:
848 	spin_lock_irqsave(ap->lock, flags);
849 
850 	while (ap->pflags & (ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS)) {
851 		prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
852 		spin_unlock_irqrestore(ap->lock, flags);
853 		schedule();
854 		spin_lock_irqsave(ap->lock, flags);
855 	}
856 	finish_wait(&ap->eh_wait_q, &wait);
857 
858 	spin_unlock_irqrestore(ap->lock, flags);
859 
860 	/* make sure SCSI EH is complete */
861 	if (scsi_host_in_recovery(ap->scsi_host)) {
862 		ata_msleep(ap, 10);
863 		goto retry;
864 	}
865 }
866 EXPORT_SYMBOL_GPL(ata_port_wait_eh);
867 
868 static int ata_eh_nr_in_flight(struct ata_port *ap)
869 {
870 	unsigned int tag;
871 	int nr = 0;
872 
873 	/* count only non-internal commands */
874 	for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++)
875 		if (ata_qc_from_tag(ap, tag))
876 			nr++;
877 
878 	return nr;
879 }
880 
881 void ata_eh_fastdrain_timerfn(unsigned long arg)
882 {
883 	struct ata_port *ap = (void *)arg;
884 	unsigned long flags;
885 	int cnt;
886 
887 	spin_lock_irqsave(ap->lock, flags);
888 
889 	cnt = ata_eh_nr_in_flight(ap);
890 
891 	/* are we done? */
892 	if (!cnt)
893 		goto out_unlock;
894 
895 	if (cnt == ap->fastdrain_cnt) {
896 		unsigned int tag;
897 
898 		/* No progress during the last interval, tag all
899 		 * in-flight qcs as timed out and freeze the port.
900 		 */
901 		for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++) {
902 			struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
903 			if (qc)
904 				qc->err_mask |= AC_ERR_TIMEOUT;
905 		}
906 
907 		ata_port_freeze(ap);
908 	} else {
909 		/* some qcs have finished, give it another chance */
910 		ap->fastdrain_cnt = cnt;
911 		ap->fastdrain_timer.expires =
912 			ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
913 		add_timer(&ap->fastdrain_timer);
914 	}
915 
916  out_unlock:
917 	spin_unlock_irqrestore(ap->lock, flags);
918 }
919 
920 /**
921  *	ata_eh_set_pending - set ATA_PFLAG_EH_PENDING and activate fast drain
922  *	@ap: target ATA port
923  *	@fastdrain: activate fast drain
924  *
925  *	Set ATA_PFLAG_EH_PENDING and activate fast drain if @fastdrain
926  *	is non-zero and EH wasn't pending before.  Fast drain ensures
927  *	that EH kicks in in timely manner.
928  *
929  *	LOCKING:
930  *	spin_lock_irqsave(host lock)
931  */
932 static void ata_eh_set_pending(struct ata_port *ap, int fastdrain)
933 {
934 	int cnt;
935 
936 	/* already scheduled? */
937 	if (ap->pflags & ATA_PFLAG_EH_PENDING)
938 		return;
939 
940 	ap->pflags |= ATA_PFLAG_EH_PENDING;
941 
942 	if (!fastdrain)
943 		return;
944 
945 	/* do we have in-flight qcs? */
946 	cnt = ata_eh_nr_in_flight(ap);
947 	if (!cnt)
948 		return;
949 
950 	/* activate fast drain */
951 	ap->fastdrain_cnt = cnt;
952 	ap->fastdrain_timer.expires =
953 		ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
954 	add_timer(&ap->fastdrain_timer);
955 }
956 
957 /**
958  *	ata_qc_schedule_eh - schedule qc for error handling
959  *	@qc: command to schedule error handling for
960  *
961  *	Schedule error handling for @qc.  EH will kick in as soon as
962  *	other commands are drained.
963  *
964  *	LOCKING:
965  *	spin_lock_irqsave(host lock)
966  */
967 void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
968 {
969 	struct ata_port *ap = qc->ap;
970 	struct request_queue *q = qc->scsicmd->device->request_queue;
971 	unsigned long flags;
972 
973 	WARN_ON(!ap->ops->error_handler);
974 
975 	qc->flags |= ATA_QCFLAG_FAILED;
976 	ata_eh_set_pending(ap, 1);
977 
978 	/* The following will fail if timeout has already expired.
979 	 * ata_scsi_error() takes care of such scmds on EH entry.
980 	 * Note that ATA_QCFLAG_FAILED is unconditionally set after
981 	 * this function completes.
982 	 */
983 	spin_lock_irqsave(q->queue_lock, flags);
984 	blk_abort_request(qc->scsicmd->request);
985 	spin_unlock_irqrestore(q->queue_lock, flags);
986 }
987 
988 /**
989  *	ata_port_schedule_eh - schedule error handling without a qc
990  *	@ap: ATA port to schedule EH for
991  *
992  *	Schedule error handling for @ap.  EH will kick in as soon as
993  *	all commands are drained.
994  *
995  *	LOCKING:
996  *	spin_lock_irqsave(host lock)
997  */
998 void ata_port_schedule_eh(struct ata_port *ap)
999 {
1000 	WARN_ON(!ap->ops->error_handler);
1001 
1002 	if (ap->pflags & ATA_PFLAG_INITIALIZING)
1003 		return;
1004 
1005 	ata_eh_set_pending(ap, 1);
1006 	scsi_schedule_eh(ap->scsi_host);
1007 
1008 	DPRINTK("port EH scheduled\n");
1009 }
1010 
1011 static int ata_do_link_abort(struct ata_port *ap, struct ata_link *link)
1012 {
1013 	int tag, nr_aborted = 0;
1014 
1015 	WARN_ON(!ap->ops->error_handler);
1016 
1017 	/* we're gonna abort all commands, no need for fast drain */
1018 	ata_eh_set_pending(ap, 0);
1019 
1020 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
1021 		struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
1022 
1023 		if (qc && (!link || qc->dev->link == link)) {
1024 			qc->flags |= ATA_QCFLAG_FAILED;
1025 			ata_qc_complete(qc);
1026 			nr_aborted++;
1027 		}
1028 	}
1029 
1030 	if (!nr_aborted)
1031 		ata_port_schedule_eh(ap);
1032 
1033 	return nr_aborted;
1034 }
1035 
1036 /**
1037  *	ata_link_abort - abort all qc's on the link
1038  *	@link: ATA link to abort qc's for
1039  *
1040  *	Abort all active qc's active on @link and schedule EH.
1041  *
1042  *	LOCKING:
1043  *	spin_lock_irqsave(host lock)
1044  *
1045  *	RETURNS:
1046  *	Number of aborted qc's.
1047  */
1048 int ata_link_abort(struct ata_link *link)
1049 {
1050 	return ata_do_link_abort(link->ap, link);
1051 }
1052 
1053 /**
1054  *	ata_port_abort - abort all qc's on the port
1055  *	@ap: ATA port to abort qc's for
1056  *
1057  *	Abort all active qc's of @ap and schedule EH.
1058  *
1059  *	LOCKING:
1060  *	spin_lock_irqsave(host_set lock)
1061  *
1062  *	RETURNS:
1063  *	Number of aborted qc's.
1064  */
1065 int ata_port_abort(struct ata_port *ap)
1066 {
1067 	return ata_do_link_abort(ap, NULL);
1068 }
1069 
1070 /**
1071  *	__ata_port_freeze - freeze port
1072  *	@ap: ATA port to freeze
1073  *
1074  *	This function is called when HSM violation or some other
1075  *	condition disrupts normal operation of the port.  Frozen port
1076  *	is not allowed to perform any operation until the port is
1077  *	thawed, which usually follows a successful reset.
1078  *
1079  *	ap->ops->freeze() callback can be used for freezing the port
1080  *	hardware-wise (e.g. mask interrupt and stop DMA engine).  If a
1081  *	port cannot be frozen hardware-wise, the interrupt handler
1082  *	must ack and clear interrupts unconditionally while the port
1083  *	is frozen.
1084  *
1085  *	LOCKING:
1086  *	spin_lock_irqsave(host lock)
1087  */
1088 static void __ata_port_freeze(struct ata_port *ap)
1089 {
1090 	WARN_ON(!ap->ops->error_handler);
1091 
1092 	if (ap->ops->freeze)
1093 		ap->ops->freeze(ap);
1094 
1095 	ap->pflags |= ATA_PFLAG_FROZEN;
1096 
1097 	DPRINTK("ata%u port frozen\n", ap->print_id);
1098 }
1099 
1100 /**
1101  *	ata_port_freeze - abort & freeze port
1102  *	@ap: ATA port to freeze
1103  *
1104  *	Abort and freeze @ap.  The freeze operation must be called
1105  *	first, because some hardware requires special operations
1106  *	before the taskfile registers are accessible.
1107  *
1108  *	LOCKING:
1109  *	spin_lock_irqsave(host lock)
1110  *
1111  *	RETURNS:
1112  *	Number of aborted commands.
1113  */
1114 int ata_port_freeze(struct ata_port *ap)
1115 {
1116 	int nr_aborted;
1117 
1118 	WARN_ON(!ap->ops->error_handler);
1119 
1120 	__ata_port_freeze(ap);
1121 	nr_aborted = ata_port_abort(ap);
1122 
1123 	return nr_aborted;
1124 }
1125 
1126 /**
1127  *	sata_async_notification - SATA async notification handler
1128  *	@ap: ATA port where async notification is received
1129  *
1130  *	Handler to be called when async notification via SDB FIS is
1131  *	received.  This function schedules EH if necessary.
1132  *
1133  *	LOCKING:
1134  *	spin_lock_irqsave(host lock)
1135  *
1136  *	RETURNS:
1137  *	1 if EH is scheduled, 0 otherwise.
1138  */
1139 int sata_async_notification(struct ata_port *ap)
1140 {
1141 	u32 sntf;
1142 	int rc;
1143 
1144 	if (!(ap->flags & ATA_FLAG_AN))
1145 		return 0;
1146 
1147 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
1148 	if (rc == 0)
1149 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
1150 
1151 	if (!sata_pmp_attached(ap) || rc) {
1152 		/* PMP is not attached or SNTF is not available */
1153 		if (!sata_pmp_attached(ap)) {
1154 			/* PMP is not attached.  Check whether ATAPI
1155 			 * AN is configured.  If so, notify media
1156 			 * change.
1157 			 */
1158 			struct ata_device *dev = ap->link.device;
1159 
1160 			if ((dev->class == ATA_DEV_ATAPI) &&
1161 			    (dev->flags & ATA_DFLAG_AN))
1162 				ata_scsi_media_change_notify(dev);
1163 			return 0;
1164 		} else {
1165 			/* PMP is attached but SNTF is not available.
1166 			 * ATAPI async media change notification is
1167 			 * not used.  The PMP must be reporting PHY
1168 			 * status change, schedule EH.
1169 			 */
1170 			ata_port_schedule_eh(ap);
1171 			return 1;
1172 		}
1173 	} else {
1174 		/* PMP is attached and SNTF is available */
1175 		struct ata_link *link;
1176 
1177 		/* check and notify ATAPI AN */
1178 		ata_for_each_link(link, ap, EDGE) {
1179 			if (!(sntf & (1 << link->pmp)))
1180 				continue;
1181 
1182 			if ((link->device->class == ATA_DEV_ATAPI) &&
1183 			    (link->device->flags & ATA_DFLAG_AN))
1184 				ata_scsi_media_change_notify(link->device);
1185 		}
1186 
1187 		/* If PMP is reporting that PHY status of some
1188 		 * downstream ports has changed, schedule EH.
1189 		 */
1190 		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
1191 			ata_port_schedule_eh(ap);
1192 			return 1;
1193 		}
1194 
1195 		return 0;
1196 	}
1197 }
1198 
1199 /**
1200  *	ata_eh_freeze_port - EH helper to freeze port
1201  *	@ap: ATA port to freeze
1202  *
1203  *	Freeze @ap.
1204  *
1205  *	LOCKING:
1206  *	None.
1207  */
1208 void ata_eh_freeze_port(struct ata_port *ap)
1209 {
1210 	unsigned long flags;
1211 
1212 	if (!ap->ops->error_handler)
1213 		return;
1214 
1215 	spin_lock_irqsave(ap->lock, flags);
1216 	__ata_port_freeze(ap);
1217 	spin_unlock_irqrestore(ap->lock, flags);
1218 }
1219 
1220 /**
1221  *	ata_port_thaw_port - EH helper to thaw port
1222  *	@ap: ATA port to thaw
1223  *
1224  *	Thaw frozen port @ap.
1225  *
1226  *	LOCKING:
1227  *	None.
1228  */
1229 void ata_eh_thaw_port(struct ata_port *ap)
1230 {
1231 	unsigned long flags;
1232 
1233 	if (!ap->ops->error_handler)
1234 		return;
1235 
1236 	spin_lock_irqsave(ap->lock, flags);
1237 
1238 	ap->pflags &= ~ATA_PFLAG_FROZEN;
1239 
1240 	if (ap->ops->thaw)
1241 		ap->ops->thaw(ap);
1242 
1243 	spin_unlock_irqrestore(ap->lock, flags);
1244 
1245 	DPRINTK("ata%u port thawed\n", ap->print_id);
1246 }
1247 
1248 static void ata_eh_scsidone(struct scsi_cmnd *scmd)
1249 {
1250 	/* nada */
1251 }
1252 
1253 static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
1254 {
1255 	struct ata_port *ap = qc->ap;
1256 	struct scsi_cmnd *scmd = qc->scsicmd;
1257 	unsigned long flags;
1258 
1259 	spin_lock_irqsave(ap->lock, flags);
1260 	qc->scsidone = ata_eh_scsidone;
1261 	__ata_qc_complete(qc);
1262 	WARN_ON(ata_tag_valid(qc->tag));
1263 	spin_unlock_irqrestore(ap->lock, flags);
1264 
1265 	scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
1266 }
1267 
1268 /**
1269  *	ata_eh_qc_complete - Complete an active ATA command from EH
1270  *	@qc: Command to complete
1271  *
1272  *	Indicate to the mid and upper layers that an ATA command has
1273  *	completed.  To be used from EH.
1274  */
1275 void ata_eh_qc_complete(struct ata_queued_cmd *qc)
1276 {
1277 	struct scsi_cmnd *scmd = qc->scsicmd;
1278 	scmd->retries = scmd->allowed;
1279 	__ata_eh_qc_complete(qc);
1280 }
1281 
1282 /**
1283  *	ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
1284  *	@qc: Command to retry
1285  *
1286  *	Indicate to the mid and upper layers that an ATA command
1287  *	should be retried.  To be used from EH.
1288  *
1289  *	SCSI midlayer limits the number of retries to scmd->allowed.
1290  *	scmd->retries is decremented for commands which get retried
1291  *	due to unrelated failures (qc->err_mask is zero).
1292  */
1293 void ata_eh_qc_retry(struct ata_queued_cmd *qc)
1294 {
1295 	struct scsi_cmnd *scmd = qc->scsicmd;
1296 	if (!qc->err_mask && scmd->retries)
1297 		scmd->retries--;
1298 	__ata_eh_qc_complete(qc);
1299 }
1300 
1301 /**
1302  *	ata_dev_disable - disable ATA device
1303  *	@dev: ATA device to disable
1304  *
1305  *	Disable @dev.
1306  *
1307  *	Locking:
1308  *	EH context.
1309  */
1310 void ata_dev_disable(struct ata_device *dev)
1311 {
1312 	if (!ata_dev_enabled(dev))
1313 		return;
1314 
1315 	if (ata_msg_drv(dev->link->ap))
1316 		ata_dev_warn(dev, "disabled\n");
1317 	ata_acpi_on_disable(dev);
1318 	ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 | ATA_DNXFER_QUIET);
1319 	dev->class++;
1320 
1321 	/* From now till the next successful probe, ering is used to
1322 	 * track probe failures.  Clear accumulated device error info.
1323 	 */
1324 	ata_ering_clear(&dev->ering);
1325 }
1326 
1327 /**
1328  *	ata_eh_detach_dev - detach ATA device
1329  *	@dev: ATA device to detach
1330  *
1331  *	Detach @dev.
1332  *
1333  *	LOCKING:
1334  *	None.
1335  */
1336 void ata_eh_detach_dev(struct ata_device *dev)
1337 {
1338 	struct ata_link *link = dev->link;
1339 	struct ata_port *ap = link->ap;
1340 	struct ata_eh_context *ehc = &link->eh_context;
1341 	unsigned long flags;
1342 
1343 	ata_dev_disable(dev);
1344 
1345 	spin_lock_irqsave(ap->lock, flags);
1346 
1347 	dev->flags &= ~ATA_DFLAG_DETACH;
1348 
1349 	if (ata_scsi_offline_dev(dev)) {
1350 		dev->flags |= ATA_DFLAG_DETACHED;
1351 		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
1352 	}
1353 
1354 	/* clear per-dev EH info */
1355 	ata_eh_clear_action(link, dev, &link->eh_info, ATA_EH_PERDEV_MASK);
1356 	ata_eh_clear_action(link, dev, &link->eh_context.i, ATA_EH_PERDEV_MASK);
1357 	ehc->saved_xfer_mode[dev->devno] = 0;
1358 	ehc->saved_ncq_enabled &= ~(1 << dev->devno);
1359 
1360 	spin_unlock_irqrestore(ap->lock, flags);
1361 }
1362 
1363 /**
1364  *	ata_eh_about_to_do - about to perform eh_action
1365  *	@link: target ATA link
1366  *	@dev: target ATA dev for per-dev action (can be NULL)
1367  *	@action: action about to be performed
1368  *
1369  *	Called just before performing EH actions to clear related bits
1370  *	in @link->eh_info such that eh actions are not unnecessarily
1371  *	repeated.
1372  *
1373  *	LOCKING:
1374  *	None.
1375  */
1376 void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
1377 			unsigned int action)
1378 {
1379 	struct ata_port *ap = link->ap;
1380 	struct ata_eh_info *ehi = &link->eh_info;
1381 	struct ata_eh_context *ehc = &link->eh_context;
1382 	unsigned long flags;
1383 
1384 	spin_lock_irqsave(ap->lock, flags);
1385 
1386 	ata_eh_clear_action(link, dev, ehi, action);
1387 
1388 	/* About to take EH action, set RECOVERED.  Ignore actions on
1389 	 * slave links as master will do them again.
1390 	 */
1391 	if (!(ehc->i.flags & ATA_EHI_QUIET) && link != ap->slave_link)
1392 		ap->pflags |= ATA_PFLAG_RECOVERED;
1393 
1394 	spin_unlock_irqrestore(ap->lock, flags);
1395 }
1396 
1397 /**
1398  *	ata_eh_done - EH action complete
1399 *	@ap: target ATA port
1400  *	@dev: target ATA dev for per-dev action (can be NULL)
1401  *	@action: action just completed
1402  *
1403  *	Called right after performing EH actions to clear related bits
1404  *	in @link->eh_context.
1405  *
1406  *	LOCKING:
1407  *	None.
1408  */
1409 void ata_eh_done(struct ata_link *link, struct ata_device *dev,
1410 		 unsigned int action)
1411 {
1412 	struct ata_eh_context *ehc = &link->eh_context;
1413 
1414 	ata_eh_clear_action(link, dev, &ehc->i, action);
1415 }
1416 
1417 /**
1418  *	ata_err_string - convert err_mask to descriptive string
1419  *	@err_mask: error mask to convert to string
1420  *
1421  *	Convert @err_mask to descriptive string.  Errors are
1422  *	prioritized according to severity and only the most severe
1423  *	error is reported.
1424  *
1425  *	LOCKING:
1426  *	None.
1427  *
1428  *	RETURNS:
1429  *	Descriptive string for @err_mask
1430  */
1431 static const char *ata_err_string(unsigned int err_mask)
1432 {
1433 	if (err_mask & AC_ERR_HOST_BUS)
1434 		return "host bus error";
1435 	if (err_mask & AC_ERR_ATA_BUS)
1436 		return "ATA bus error";
1437 	if (err_mask & AC_ERR_TIMEOUT)
1438 		return "timeout";
1439 	if (err_mask & AC_ERR_HSM)
1440 		return "HSM violation";
1441 	if (err_mask & AC_ERR_SYSTEM)
1442 		return "internal error";
1443 	if (err_mask & AC_ERR_MEDIA)
1444 		return "media error";
1445 	if (err_mask & AC_ERR_INVALID)
1446 		return "invalid argument";
1447 	if (err_mask & AC_ERR_DEV)
1448 		return "device error";
1449 	return "unknown error";
1450 }
1451 
1452 /**
1453  *	ata_read_log_page - read a specific log page
1454  *	@dev: target device
1455  *	@page: page to read
1456  *	@buf: buffer to store read page
1457  *	@sectors: number of sectors to read
1458  *
1459  *	Read log page using READ_LOG_EXT command.
1460  *
1461  *	LOCKING:
1462  *	Kernel thread context (may sleep).
1463  *
1464  *	RETURNS:
1465  *	0 on success, AC_ERR_* mask otherwise.
1466  */
1467 static unsigned int ata_read_log_page(struct ata_device *dev,
1468 				      u8 page, void *buf, unsigned int sectors)
1469 {
1470 	struct ata_taskfile tf;
1471 	unsigned int err_mask;
1472 
1473 	DPRINTK("read log page - page %d\n", page);
1474 
1475 	ata_tf_init(dev, &tf);
1476 	tf.command = ATA_CMD_READ_LOG_EXT;
1477 	tf.lbal = page;
1478 	tf.nsect = sectors;
1479 	tf.hob_nsect = sectors >> 8;
1480 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_LBA48 | ATA_TFLAG_DEVICE;
1481 	tf.protocol = ATA_PROT_PIO;
1482 
1483 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
1484 				     buf, sectors * ATA_SECT_SIZE, 0);
1485 
1486 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
1487 	return err_mask;
1488 }
1489 
1490 /**
1491  *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
1492  *	@dev: Device to read log page 10h from
1493  *	@tag: Resulting tag of the failed command
1494  *	@tf: Resulting taskfile registers of the failed command
1495  *
1496  *	Read log page 10h to obtain NCQ error details and clear error
1497  *	condition.
1498  *
1499  *	LOCKING:
1500  *	Kernel thread context (may sleep).
1501  *
1502  *	RETURNS:
1503  *	0 on success, -errno otherwise.
1504  */
1505 static int ata_eh_read_log_10h(struct ata_device *dev,
1506 			       int *tag, struct ata_taskfile *tf)
1507 {
1508 	u8 *buf = dev->link->ap->sector_buf;
1509 	unsigned int err_mask;
1510 	u8 csum;
1511 	int i;
1512 
1513 	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, buf, 1);
1514 	if (err_mask)
1515 		return -EIO;
1516 
1517 	csum = 0;
1518 	for (i = 0; i < ATA_SECT_SIZE; i++)
1519 		csum += buf[i];
1520 	if (csum)
1521 		ata_dev_warn(dev, "invalid checksum 0x%x on log page 10h\n",
1522 			     csum);
1523 
1524 	if (buf[0] & 0x80)
1525 		return -ENOENT;
1526 
1527 	*tag = buf[0] & 0x1f;
1528 
1529 	tf->command = buf[2];
1530 	tf->feature = buf[3];
1531 	tf->lbal = buf[4];
1532 	tf->lbam = buf[5];
1533 	tf->lbah = buf[6];
1534 	tf->device = buf[7];
1535 	tf->hob_lbal = buf[8];
1536 	tf->hob_lbam = buf[9];
1537 	tf->hob_lbah = buf[10];
1538 	tf->nsect = buf[12];
1539 	tf->hob_nsect = buf[13];
1540 
1541 	return 0;
1542 }
1543 
1544 /**
1545  *	atapi_eh_tur - perform ATAPI TEST_UNIT_READY
1546  *	@dev: target ATAPI device
1547  *	@r_sense_key: out parameter for sense_key
1548  *
1549  *	Perform ATAPI TEST_UNIT_READY.
1550  *
1551  *	LOCKING:
1552  *	EH context (may sleep).
1553  *
1554  *	RETURNS:
1555  *	0 on success, AC_ERR_* mask on failure.
1556  */
1557 static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
1558 {
1559 	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
1560 	struct ata_taskfile tf;
1561 	unsigned int err_mask;
1562 
1563 	ata_tf_init(dev, &tf);
1564 
1565 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1566 	tf.command = ATA_CMD_PACKET;
1567 	tf.protocol = ATAPI_PROT_NODATA;
1568 
1569 	err_mask = ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
1570 	if (err_mask == AC_ERR_DEV)
1571 		*r_sense_key = tf.feature >> 4;
1572 	return err_mask;
1573 }
1574 
1575 /**
1576  *	atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
1577  *	@dev: device to perform REQUEST_SENSE to
1578  *	@sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long)
1579  *	@dfl_sense_key: default sense key to use
1580  *
1581  *	Perform ATAPI REQUEST_SENSE after the device reported CHECK
1582  *	SENSE.  This function is EH helper.
1583  *
1584  *	LOCKING:
1585  *	Kernel thread context (may sleep).
1586  *
1587  *	RETURNS:
1588  *	0 on success, AC_ERR_* mask on failure
1589  */
1590 static unsigned int atapi_eh_request_sense(struct ata_device *dev,
1591 					   u8 *sense_buf, u8 dfl_sense_key)
1592 {
1593 	u8 cdb[ATAPI_CDB_LEN] =
1594 		{ REQUEST_SENSE, 0, 0, 0, SCSI_SENSE_BUFFERSIZE, 0 };
1595 	struct ata_port *ap = dev->link->ap;
1596 	struct ata_taskfile tf;
1597 
1598 	DPRINTK("ATAPI request sense\n");
1599 
1600 	/* FIXME: is this needed? */
1601 	memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
1602 
1603 	/* initialize sense_buf with the error register,
1604 	 * for the case where they are -not- overwritten
1605 	 */
1606 	sense_buf[0] = 0x70;
1607 	sense_buf[2] = dfl_sense_key;
1608 
1609 	/* some devices time out if garbage left in tf */
1610 	ata_tf_init(dev, &tf);
1611 
1612 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1613 	tf.command = ATA_CMD_PACKET;
1614 
1615 	/* is it pointless to prefer PIO for "safety reasons"? */
1616 	if (ap->flags & ATA_FLAG_PIO_DMA) {
1617 		tf.protocol = ATAPI_PROT_DMA;
1618 		tf.feature |= ATAPI_PKT_DMA;
1619 	} else {
1620 		tf.protocol = ATAPI_PROT_PIO;
1621 		tf.lbam = SCSI_SENSE_BUFFERSIZE;
1622 		tf.lbah = 0;
1623 	}
1624 
1625 	return ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
1626 				 sense_buf, SCSI_SENSE_BUFFERSIZE, 0);
1627 }
1628 
1629 /**
1630  *	ata_eh_analyze_serror - analyze SError for a failed port
1631  *	@link: ATA link to analyze SError for
1632  *
1633  *	Analyze SError if available and further determine cause of
1634  *	failure.
1635  *
1636  *	LOCKING:
1637  *	None.
1638  */
1639 static void ata_eh_analyze_serror(struct ata_link *link)
1640 {
1641 	struct ata_eh_context *ehc = &link->eh_context;
1642 	u32 serror = ehc->i.serror;
1643 	unsigned int err_mask = 0, action = 0;
1644 	u32 hotplug_mask;
1645 
1646 	if (serror & (SERR_PERSISTENT | SERR_DATA)) {
1647 		err_mask |= AC_ERR_ATA_BUS;
1648 		action |= ATA_EH_RESET;
1649 	}
1650 	if (serror & SERR_PROTOCOL) {
1651 		err_mask |= AC_ERR_HSM;
1652 		action |= ATA_EH_RESET;
1653 	}
1654 	if (serror & SERR_INTERNAL) {
1655 		err_mask |= AC_ERR_SYSTEM;
1656 		action |= ATA_EH_RESET;
1657 	}
1658 
1659 	/* Determine whether a hotplug event has occurred.  Both
1660 	 * SError.N/X are considered hotplug events for enabled or
1661 	 * host links.  For disabled PMP links, only N bit is
1662 	 * considered as X bit is left at 1 for link plugging.
1663 	 */
1664 	if (link->lpm_policy > ATA_LPM_MAX_POWER)
1665 		hotplug_mask = 0;	/* hotplug doesn't work w/ LPM */
1666 	else if (!(link->flags & ATA_LFLAG_DISABLED) || ata_is_host_link(link))
1667 		hotplug_mask = SERR_PHYRDY_CHG | SERR_DEV_XCHG;
1668 	else
1669 		hotplug_mask = SERR_PHYRDY_CHG;
1670 
1671 	if (serror & hotplug_mask)
1672 		ata_ehi_hotplugged(&ehc->i);
1673 
1674 	ehc->i.err_mask |= err_mask;
1675 	ehc->i.action |= action;
1676 }
1677 
1678 /**
1679  *	ata_eh_analyze_ncq_error - analyze NCQ error
1680  *	@link: ATA link to analyze NCQ error for
1681  *
1682  *	Read log page 10h, determine the offending qc and acquire
1683  *	error status TF.  For NCQ device errors, all LLDDs have to do
1684  *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
1685  *	care of the rest.
1686  *
1687  *	LOCKING:
1688  *	Kernel thread context (may sleep).
1689  */
1690 void ata_eh_analyze_ncq_error(struct ata_link *link)
1691 {
1692 	struct ata_port *ap = link->ap;
1693 	struct ata_eh_context *ehc = &link->eh_context;
1694 	struct ata_device *dev = link->device;
1695 	struct ata_queued_cmd *qc;
1696 	struct ata_taskfile tf;
1697 	int tag, rc;
1698 
1699 	/* if frozen, we can't do much */
1700 	if (ap->pflags & ATA_PFLAG_FROZEN)
1701 		return;
1702 
1703 	/* is it NCQ device error? */
1704 	if (!link->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
1705 		return;
1706 
1707 	/* has LLDD analyzed already? */
1708 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
1709 		qc = __ata_qc_from_tag(ap, tag);
1710 
1711 		if (!(qc->flags & ATA_QCFLAG_FAILED))
1712 			continue;
1713 
1714 		if (qc->err_mask)
1715 			return;
1716 	}
1717 
1718 	/* okay, this error is ours */
1719 	memset(&tf, 0, sizeof(tf));
1720 	rc = ata_eh_read_log_10h(dev, &tag, &tf);
1721 	if (rc) {
1722 		ata_link_err(link, "failed to read log page 10h (errno=%d)\n",
1723 			     rc);
1724 		return;
1725 	}
1726 
1727 	if (!(link->sactive & (1 << tag))) {
1728 		ata_link_err(link, "log page 10h reported inactive tag %d\n",
1729 			     tag);
1730 		return;
1731 	}
1732 
1733 	/* we've got the perpetrator, condemn it */
1734 	qc = __ata_qc_from_tag(ap, tag);
1735 	memcpy(&qc->result_tf, &tf, sizeof(tf));
1736 	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
1737 	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
1738 	ehc->i.err_mask &= ~AC_ERR_DEV;
1739 }
1740 
1741 /**
1742  *	ata_eh_analyze_tf - analyze taskfile of a failed qc
1743  *	@qc: qc to analyze
1744  *	@tf: Taskfile registers to analyze
1745  *
1746  *	Analyze taskfile of @qc and further determine cause of
1747  *	failure.  This function also requests ATAPI sense data if
1748  *	available.
1749  *
1750  *	LOCKING:
1751  *	Kernel thread context (may sleep).
1752  *
1753  *	RETURNS:
1754  *	Determined recovery action
1755  */
1756 static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc,
1757 				      const struct ata_taskfile *tf)
1758 {
1759 	unsigned int tmp, action = 0;
1760 	u8 stat = tf->command, err = tf->feature;
1761 
1762 	if ((stat & (ATA_BUSY | ATA_DRQ | ATA_DRDY)) != ATA_DRDY) {
1763 		qc->err_mask |= AC_ERR_HSM;
1764 		return ATA_EH_RESET;
1765 	}
1766 
1767 	if (stat & (ATA_ERR | ATA_DF))
1768 		qc->err_mask |= AC_ERR_DEV;
1769 	else
1770 		return 0;
1771 
1772 	switch (qc->dev->class) {
1773 	case ATA_DEV_ATA:
1774 		if (err & ATA_ICRC)
1775 			qc->err_mask |= AC_ERR_ATA_BUS;
1776 		if (err & ATA_UNC)
1777 			qc->err_mask |= AC_ERR_MEDIA;
1778 		if (err & ATA_IDNF)
1779 			qc->err_mask |= AC_ERR_INVALID;
1780 		break;
1781 
1782 	case ATA_DEV_ATAPI:
1783 		if (!(qc->ap->pflags & ATA_PFLAG_FROZEN)) {
1784 			tmp = atapi_eh_request_sense(qc->dev,
1785 						qc->scsicmd->sense_buffer,
1786 						qc->result_tf.feature >> 4);
1787 			if (!tmp) {
1788 				/* ATA_QCFLAG_SENSE_VALID is used to
1789 				 * tell atapi_qc_complete() that sense
1790 				 * data is already valid.
1791 				 *
1792 				 * TODO: interpret sense data and set
1793 				 * appropriate err_mask.
1794 				 */
1795 				qc->flags |= ATA_QCFLAG_SENSE_VALID;
1796 			} else
1797 				qc->err_mask |= tmp;
1798 		}
1799 	}
1800 
1801 	if (qc->err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT | AC_ERR_ATA_BUS))
1802 		action |= ATA_EH_RESET;
1803 
1804 	return action;
1805 }
1806 
1807 static int ata_eh_categorize_error(unsigned int eflags, unsigned int err_mask,
1808 				   int *xfer_ok)
1809 {
1810 	int base = 0;
1811 
1812 	if (!(eflags & ATA_EFLAG_DUBIOUS_XFER))
1813 		*xfer_ok = 1;
1814 
1815 	if (!*xfer_ok)
1816 		base = ATA_ECAT_DUBIOUS_NONE;
1817 
1818 	if (err_mask & AC_ERR_ATA_BUS)
1819 		return base + ATA_ECAT_ATA_BUS;
1820 
1821 	if (err_mask & AC_ERR_TIMEOUT)
1822 		return base + ATA_ECAT_TOUT_HSM;
1823 
1824 	if (eflags & ATA_EFLAG_IS_IO) {
1825 		if (err_mask & AC_ERR_HSM)
1826 			return base + ATA_ECAT_TOUT_HSM;
1827 		if ((err_mask &
1828 		     (AC_ERR_DEV|AC_ERR_MEDIA|AC_ERR_INVALID)) == AC_ERR_DEV)
1829 			return base + ATA_ECAT_UNK_DEV;
1830 	}
1831 
1832 	return 0;
1833 }
1834 
1835 struct speed_down_verdict_arg {
1836 	u64 since;
1837 	int xfer_ok;
1838 	int nr_errors[ATA_ECAT_NR];
1839 };
1840 
1841 static int speed_down_verdict_cb(struct ata_ering_entry *ent, void *void_arg)
1842 {
1843 	struct speed_down_verdict_arg *arg = void_arg;
1844 	int cat;
1845 
1846 	if ((ent->eflags & ATA_EFLAG_OLD_ER) || (ent->timestamp < arg->since))
1847 		return -1;
1848 
1849 	cat = ata_eh_categorize_error(ent->eflags, ent->err_mask,
1850 				      &arg->xfer_ok);
1851 	arg->nr_errors[cat]++;
1852 
1853 	return 0;
1854 }
1855 
1856 /**
1857  *	ata_eh_speed_down_verdict - Determine speed down verdict
1858  *	@dev: Device of interest
1859  *
1860  *	This function examines error ring of @dev and determines
1861  *	whether NCQ needs to be turned off, transfer speed should be
1862  *	stepped down, or falling back to PIO is necessary.
1863  *
1864  *	ECAT_ATA_BUS	: ATA_BUS error for any command
1865  *
1866  *	ECAT_TOUT_HSM	: TIMEOUT for any command or HSM violation for
1867  *			  IO commands
1868  *
1869  *	ECAT_UNK_DEV	: Unknown DEV error for IO commands
1870  *
1871  *	ECAT_DUBIOUS_*	: Identical to above three but occurred while
1872  *			  data transfer hasn't been verified.
1873  *
1874  *	Verdicts are
1875  *
1876  *	NCQ_OFF		: Turn off NCQ.
1877  *
1878  *	SPEED_DOWN	: Speed down transfer speed but don't fall back
1879  *			  to PIO.
1880  *
1881  *	FALLBACK_TO_PIO	: Fall back to PIO.
1882  *
1883  *	Even if multiple verdicts are returned, only one action is
1884  *	taken per error.  An action triggered by non-DUBIOUS errors
1885  *	clears ering, while one triggered by DUBIOUS_* errors doesn't.
1886  *	This is to expedite speed down decisions right after device is
1887  *	initially configured.
1888  *
1889  *	The followings are speed down rules.  #1 and #2 deal with
1890  *	DUBIOUS errors.
1891  *
1892  *	1. If more than one DUBIOUS_ATA_BUS or DUBIOUS_TOUT_HSM errors
1893  *	   occurred during last 5 mins, SPEED_DOWN and FALLBACK_TO_PIO.
1894  *
1895  *	2. If more than one DUBIOUS_TOUT_HSM or DUBIOUS_UNK_DEV errors
1896  *	   occurred during last 5 mins, NCQ_OFF.
1897  *
1898  *	3. If more than 8 ATA_BUS, TOUT_HSM or UNK_DEV errors
1899  *	   occurred during last 5 mins, FALLBACK_TO_PIO
1900  *
1901  *	4. If more than 3 TOUT_HSM or UNK_DEV errors occurred
1902  *	   during last 10 mins, NCQ_OFF.
1903  *
1904  *	5. If more than 3 ATA_BUS or TOUT_HSM errors, or more than 6
1905  *	   UNK_DEV errors occurred during last 10 mins, SPEED_DOWN.
1906  *
1907  *	LOCKING:
1908  *	Inherited from caller.
1909  *
1910  *	RETURNS:
1911  *	OR of ATA_EH_SPDN_* flags.
1912  */
1913 static unsigned int ata_eh_speed_down_verdict(struct ata_device *dev)
1914 {
1915 	const u64 j5mins = 5LLU * 60 * HZ, j10mins = 10LLU * 60 * HZ;
1916 	u64 j64 = get_jiffies_64();
1917 	struct speed_down_verdict_arg arg;
1918 	unsigned int verdict = 0;
1919 
1920 	/* scan past 5 mins of error history */
1921 	memset(&arg, 0, sizeof(arg));
1922 	arg.since = j64 - min(j64, j5mins);
1923 	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
1924 
1925 	if (arg.nr_errors[ATA_ECAT_DUBIOUS_ATA_BUS] +
1926 	    arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] > 1)
1927 		verdict |= ATA_EH_SPDN_SPEED_DOWN |
1928 			ATA_EH_SPDN_FALLBACK_TO_PIO | ATA_EH_SPDN_KEEP_ERRORS;
1929 
1930 	if (arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] +
1931 	    arg.nr_errors[ATA_ECAT_DUBIOUS_UNK_DEV] > 1)
1932 		verdict |= ATA_EH_SPDN_NCQ_OFF | ATA_EH_SPDN_KEEP_ERRORS;
1933 
1934 	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1935 	    arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1936 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1937 		verdict |= ATA_EH_SPDN_FALLBACK_TO_PIO;
1938 
1939 	/* scan past 10 mins of error history */
1940 	memset(&arg, 0, sizeof(arg));
1941 	arg.since = j64 - min(j64, j10mins);
1942 	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
1943 
1944 	if (arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1945 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 3)
1946 		verdict |= ATA_EH_SPDN_NCQ_OFF;
1947 
1948 	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1949 	    arg.nr_errors[ATA_ECAT_TOUT_HSM] > 3 ||
1950 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1951 		verdict |= ATA_EH_SPDN_SPEED_DOWN;
1952 
1953 	return verdict;
1954 }
1955 
1956 /**
1957  *	ata_eh_speed_down - record error and speed down if necessary
1958  *	@dev: Failed device
1959  *	@eflags: mask of ATA_EFLAG_* flags
1960  *	@err_mask: err_mask of the error
1961  *
1962  *	Record error and examine error history to determine whether
1963  *	adjusting transmission speed is necessary.  It also sets
1964  *	transmission limits appropriately if such adjustment is
1965  *	necessary.
1966  *
1967  *	LOCKING:
1968  *	Kernel thread context (may sleep).
1969  *
1970  *	RETURNS:
1971  *	Determined recovery action.
1972  */
1973 static unsigned int ata_eh_speed_down(struct ata_device *dev,
1974 				unsigned int eflags, unsigned int err_mask)
1975 {
1976 	struct ata_link *link = ata_dev_phys_link(dev);
1977 	int xfer_ok = 0;
1978 	unsigned int verdict;
1979 	unsigned int action = 0;
1980 
1981 	/* don't bother if Cat-0 error */
1982 	if (ata_eh_categorize_error(eflags, err_mask, &xfer_ok) == 0)
1983 		return 0;
1984 
1985 	/* record error and determine whether speed down is necessary */
1986 	ata_ering_record(&dev->ering, eflags, err_mask);
1987 	verdict = ata_eh_speed_down_verdict(dev);
1988 
1989 	/* turn off NCQ? */
1990 	if ((verdict & ATA_EH_SPDN_NCQ_OFF) &&
1991 	    (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ |
1992 			   ATA_DFLAG_NCQ_OFF)) == ATA_DFLAG_NCQ) {
1993 		dev->flags |= ATA_DFLAG_NCQ_OFF;
1994 		ata_dev_warn(dev, "NCQ disabled due to excessive errors\n");
1995 		goto done;
1996 	}
1997 
1998 	/* speed down? */
1999 	if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
2000 		/* speed down SATA link speed if possible */
2001 		if (sata_down_spd_limit(link, 0) == 0) {
2002 			action |= ATA_EH_RESET;
2003 			goto done;
2004 		}
2005 
2006 		/* lower transfer mode */
2007 		if (dev->spdn_cnt < 2) {
2008 			static const int dma_dnxfer_sel[] =
2009 				{ ATA_DNXFER_DMA, ATA_DNXFER_40C };
2010 			static const int pio_dnxfer_sel[] =
2011 				{ ATA_DNXFER_PIO, ATA_DNXFER_FORCE_PIO0 };
2012 			int sel;
2013 
2014 			if (dev->xfer_shift != ATA_SHIFT_PIO)
2015 				sel = dma_dnxfer_sel[dev->spdn_cnt];
2016 			else
2017 				sel = pio_dnxfer_sel[dev->spdn_cnt];
2018 
2019 			dev->spdn_cnt++;
2020 
2021 			if (ata_down_xfermask_limit(dev, sel) == 0) {
2022 				action |= ATA_EH_RESET;
2023 				goto done;
2024 			}
2025 		}
2026 	}
2027 
2028 	/* Fall back to PIO?  Slowing down to PIO is meaningless for
2029 	 * SATA ATA devices.  Consider it only for PATA and SATAPI.
2030 	 */
2031 	if ((verdict & ATA_EH_SPDN_FALLBACK_TO_PIO) && (dev->spdn_cnt >= 2) &&
2032 	    (link->ap->cbl != ATA_CBL_SATA || dev->class == ATA_DEV_ATAPI) &&
2033 	    (dev->xfer_shift != ATA_SHIFT_PIO)) {
2034 		if (ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO) == 0) {
2035 			dev->spdn_cnt = 0;
2036 			action |= ATA_EH_RESET;
2037 			goto done;
2038 		}
2039 	}
2040 
2041 	return 0;
2042  done:
2043 	/* device has been slowed down, blow error history */
2044 	if (!(verdict & ATA_EH_SPDN_KEEP_ERRORS))
2045 		ata_ering_clear(&dev->ering);
2046 	return action;
2047 }
2048 
2049 /**
2050  *	ata_eh_worth_retry - analyze error and decide whether to retry
2051  *	@qc: qc to possibly retry
2052  *
2053  *	Look at the cause of the error and decide if a retry
2054  * 	might be useful or not.  We don't want to retry media errors
2055  *	because the drive itself has probably already taken 10-30 seconds
2056  *	doing its own internal retries before reporting the failure.
2057  */
2058 static inline int ata_eh_worth_retry(struct ata_queued_cmd *qc)
2059 {
2060 	if (qc->flags & AC_ERR_MEDIA)
2061 		return 0;	/* don't retry media errors */
2062 	if (qc->flags & ATA_QCFLAG_IO)
2063 		return 1;	/* otherwise retry anything from fs stack */
2064 	if (qc->err_mask & AC_ERR_INVALID)
2065 		return 0;	/* don't retry these */
2066 	return qc->err_mask != AC_ERR_DEV;  /* retry if not dev error */
2067 }
2068 
2069 /**
2070  *	ata_eh_link_autopsy - analyze error and determine recovery action
2071  *	@link: host link to perform autopsy on
2072  *
2073  *	Analyze why @link failed and determine which recovery actions
2074  *	are needed.  This function also sets more detailed AC_ERR_*
2075  *	values and fills sense data for ATAPI CHECK SENSE.
2076  *
2077  *	LOCKING:
2078  *	Kernel thread context (may sleep).
2079  */
2080 static void ata_eh_link_autopsy(struct ata_link *link)
2081 {
2082 	struct ata_port *ap = link->ap;
2083 	struct ata_eh_context *ehc = &link->eh_context;
2084 	struct ata_device *dev;
2085 	unsigned int all_err_mask = 0, eflags = 0;
2086 	int tag;
2087 	u32 serror;
2088 	int rc;
2089 
2090 	DPRINTK("ENTER\n");
2091 
2092 	if (ehc->i.flags & ATA_EHI_NO_AUTOPSY)
2093 		return;
2094 
2095 	/* obtain and analyze SError */
2096 	rc = sata_scr_read(link, SCR_ERROR, &serror);
2097 	if (rc == 0) {
2098 		ehc->i.serror |= serror;
2099 		ata_eh_analyze_serror(link);
2100 	} else if (rc != -EOPNOTSUPP) {
2101 		/* SError read failed, force reset and probing */
2102 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
2103 		ehc->i.action |= ATA_EH_RESET;
2104 		ehc->i.err_mask |= AC_ERR_OTHER;
2105 	}
2106 
2107 	/* analyze NCQ failure */
2108 	ata_eh_analyze_ncq_error(link);
2109 
2110 	/* any real error trumps AC_ERR_OTHER */
2111 	if (ehc->i.err_mask & ~AC_ERR_OTHER)
2112 		ehc->i.err_mask &= ~AC_ERR_OTHER;
2113 
2114 	all_err_mask |= ehc->i.err_mask;
2115 
2116 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2117 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2118 
2119 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2120 		    ata_dev_phys_link(qc->dev) != link)
2121 			continue;
2122 
2123 		/* inherit upper level err_mask */
2124 		qc->err_mask |= ehc->i.err_mask;
2125 
2126 		/* analyze TF */
2127 		ehc->i.action |= ata_eh_analyze_tf(qc, &qc->result_tf);
2128 
2129 		/* DEV errors are probably spurious in case of ATA_BUS error */
2130 		if (qc->err_mask & AC_ERR_ATA_BUS)
2131 			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_MEDIA |
2132 					  AC_ERR_INVALID);
2133 
2134 		/* any real error trumps unknown error */
2135 		if (qc->err_mask & ~AC_ERR_OTHER)
2136 			qc->err_mask &= ~AC_ERR_OTHER;
2137 
2138 		/* SENSE_VALID trumps dev/unknown error and revalidation */
2139 		if (qc->flags & ATA_QCFLAG_SENSE_VALID)
2140 			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
2141 
2142 		/* determine whether the command is worth retrying */
2143 		if (ata_eh_worth_retry(qc))
2144 			qc->flags |= ATA_QCFLAG_RETRY;
2145 
2146 		/* accumulate error info */
2147 		ehc->i.dev = qc->dev;
2148 		all_err_mask |= qc->err_mask;
2149 		if (qc->flags & ATA_QCFLAG_IO)
2150 			eflags |= ATA_EFLAG_IS_IO;
2151 	}
2152 
2153 	/* enforce default EH actions */
2154 	if (ap->pflags & ATA_PFLAG_FROZEN ||
2155 	    all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
2156 		ehc->i.action |= ATA_EH_RESET;
2157 	else if (((eflags & ATA_EFLAG_IS_IO) && all_err_mask) ||
2158 		 (!(eflags & ATA_EFLAG_IS_IO) && (all_err_mask & ~AC_ERR_DEV)))
2159 		ehc->i.action |= ATA_EH_REVALIDATE;
2160 
2161 	/* If we have offending qcs and the associated failed device,
2162 	 * perform per-dev EH action only on the offending device.
2163 	 */
2164 	if (ehc->i.dev) {
2165 		ehc->i.dev_action[ehc->i.dev->devno] |=
2166 			ehc->i.action & ATA_EH_PERDEV_MASK;
2167 		ehc->i.action &= ~ATA_EH_PERDEV_MASK;
2168 	}
2169 
2170 	/* propagate timeout to host link */
2171 	if ((all_err_mask & AC_ERR_TIMEOUT) && !ata_is_host_link(link))
2172 		ap->link.eh_context.i.err_mask |= AC_ERR_TIMEOUT;
2173 
2174 	/* record error and consider speeding down */
2175 	dev = ehc->i.dev;
2176 	if (!dev && ((ata_link_max_devices(link) == 1 &&
2177 		      ata_dev_enabled(link->device))))
2178 	    dev = link->device;
2179 
2180 	if (dev) {
2181 		if (dev->flags & ATA_DFLAG_DUBIOUS_XFER)
2182 			eflags |= ATA_EFLAG_DUBIOUS_XFER;
2183 		ehc->i.action |= ata_eh_speed_down(dev, eflags, all_err_mask);
2184 	}
2185 
2186 	DPRINTK("EXIT\n");
2187 }
2188 
2189 /**
2190  *	ata_eh_autopsy - analyze error and determine recovery action
2191  *	@ap: host port to perform autopsy on
2192  *
2193  *	Analyze all links of @ap and determine why they failed and
2194  *	which recovery actions are needed.
2195  *
2196  *	LOCKING:
2197  *	Kernel thread context (may sleep).
2198  */
2199 void ata_eh_autopsy(struct ata_port *ap)
2200 {
2201 	struct ata_link *link;
2202 
2203 	ata_for_each_link(link, ap, EDGE)
2204 		ata_eh_link_autopsy(link);
2205 
2206 	/* Handle the frigging slave link.  Autopsy is done similarly
2207 	 * but actions and flags are transferred over to the master
2208 	 * link and handled from there.
2209 	 */
2210 	if (ap->slave_link) {
2211 		struct ata_eh_context *mehc = &ap->link.eh_context;
2212 		struct ata_eh_context *sehc = &ap->slave_link->eh_context;
2213 
2214 		/* transfer control flags from master to slave */
2215 		sehc->i.flags |= mehc->i.flags & ATA_EHI_TO_SLAVE_MASK;
2216 
2217 		/* perform autopsy on the slave link */
2218 		ata_eh_link_autopsy(ap->slave_link);
2219 
2220 		/* transfer actions from slave to master and clear slave */
2221 		ata_eh_about_to_do(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
2222 		mehc->i.action		|= sehc->i.action;
2223 		mehc->i.dev_action[1]	|= sehc->i.dev_action[1];
2224 		mehc->i.flags		|= sehc->i.flags;
2225 		ata_eh_done(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
2226 	}
2227 
2228 	/* Autopsy of fanout ports can affect host link autopsy.
2229 	 * Perform host link autopsy last.
2230 	 */
2231 	if (sata_pmp_attached(ap))
2232 		ata_eh_link_autopsy(&ap->link);
2233 }
2234 
2235 /**
2236  *	ata_get_cmd_descript - get description for ATA command
2237  *	@command: ATA command code to get description for
2238  *
2239  *	Return a textual description of the given command, or NULL if the
2240  *	command is not known.
2241  *
2242  *	LOCKING:
2243  *	None
2244  */
2245 const char *ata_get_cmd_descript(u8 command)
2246 {
2247 #ifdef CONFIG_ATA_VERBOSE_ERROR
2248 	static const struct
2249 	{
2250 		u8 command;
2251 		const char *text;
2252 	} cmd_descr[] = {
2253 		{ ATA_CMD_DEV_RESET,		"DEVICE RESET" },
2254 		{ ATA_CMD_CHK_POWER, 		"CHECK POWER MODE" },
2255 		{ ATA_CMD_STANDBY, 		"STANDBY" },
2256 		{ ATA_CMD_IDLE, 		"IDLE" },
2257 		{ ATA_CMD_EDD, 			"EXECUTE DEVICE DIAGNOSTIC" },
2258 		{ ATA_CMD_DOWNLOAD_MICRO,   	"DOWNLOAD MICROCODE" },
2259 		{ ATA_CMD_NOP,			"NOP" },
2260 		{ ATA_CMD_FLUSH, 		"FLUSH CACHE" },
2261 		{ ATA_CMD_FLUSH_EXT, 		"FLUSH CACHE EXT" },
2262 		{ ATA_CMD_ID_ATA,  		"IDENTIFY DEVICE" },
2263 		{ ATA_CMD_ID_ATAPI, 		"IDENTIFY PACKET DEVICE" },
2264 		{ ATA_CMD_SERVICE, 		"SERVICE" },
2265 		{ ATA_CMD_READ, 		"READ DMA" },
2266 		{ ATA_CMD_READ_EXT, 		"READ DMA EXT" },
2267 		{ ATA_CMD_READ_QUEUED, 		"READ DMA QUEUED" },
2268 		{ ATA_CMD_READ_STREAM_EXT, 	"READ STREAM EXT" },
2269 		{ ATA_CMD_READ_STREAM_DMA_EXT,  "READ STREAM DMA EXT" },
2270 		{ ATA_CMD_WRITE, 		"WRITE DMA" },
2271 		{ ATA_CMD_WRITE_EXT, 		"WRITE DMA EXT" },
2272 		{ ATA_CMD_WRITE_QUEUED, 	"WRITE DMA QUEUED EXT" },
2273 		{ ATA_CMD_WRITE_STREAM_EXT, 	"WRITE STREAM EXT" },
2274 		{ ATA_CMD_WRITE_STREAM_DMA_EXT, "WRITE STREAM DMA EXT" },
2275 		{ ATA_CMD_WRITE_FUA_EXT,	"WRITE DMA FUA EXT" },
2276 		{ ATA_CMD_WRITE_QUEUED_FUA_EXT, "WRITE DMA QUEUED FUA EXT" },
2277 		{ ATA_CMD_FPDMA_READ,		"READ FPDMA QUEUED" },
2278 		{ ATA_CMD_FPDMA_WRITE,		"WRITE FPDMA QUEUED" },
2279 		{ ATA_CMD_PIO_READ,		"READ SECTOR(S)" },
2280 		{ ATA_CMD_PIO_READ_EXT,		"READ SECTOR(S) EXT" },
2281 		{ ATA_CMD_PIO_WRITE,		"WRITE SECTOR(S)" },
2282 		{ ATA_CMD_PIO_WRITE_EXT,	"WRITE SECTOR(S) EXT" },
2283 		{ ATA_CMD_READ_MULTI,		"READ MULTIPLE" },
2284 		{ ATA_CMD_READ_MULTI_EXT,	"READ MULTIPLE EXT" },
2285 		{ ATA_CMD_WRITE_MULTI,		"WRITE MULTIPLE" },
2286 		{ ATA_CMD_WRITE_MULTI_EXT,	"WRITE MULTIPLE EXT" },
2287 		{ ATA_CMD_WRITE_MULTI_FUA_EXT, 	"WRITE MULTIPLE FUA EXT" },
2288 		{ ATA_CMD_SET_FEATURES,		"SET FEATURES" },
2289 		{ ATA_CMD_SET_MULTI,		"SET MULTIPLE MODE" },
2290 		{ ATA_CMD_VERIFY,		"READ VERIFY SECTOR(S)" },
2291 		{ ATA_CMD_VERIFY_EXT,		"READ VERIFY SECTOR(S) EXT" },
2292 		{ ATA_CMD_WRITE_UNCORR_EXT,	"WRITE UNCORRECTABLE EXT" },
2293 		{ ATA_CMD_STANDBYNOW1,		"STANDBY IMMEDIATE" },
2294 		{ ATA_CMD_IDLEIMMEDIATE,	"IDLE IMMEDIATE" },
2295 		{ ATA_CMD_SLEEP,		"SLEEP" },
2296 		{ ATA_CMD_INIT_DEV_PARAMS,	"INITIALIZE DEVICE PARAMETERS" },
2297 		{ ATA_CMD_READ_NATIVE_MAX,	"READ NATIVE MAX ADDRESS" },
2298 		{ ATA_CMD_READ_NATIVE_MAX_EXT,	"READ NATIVE MAX ADDRESS EXT" },
2299 		{ ATA_CMD_SET_MAX,		"SET MAX ADDRESS" },
2300 		{ ATA_CMD_SET_MAX_EXT,		"SET MAX ADDRESS EXT" },
2301 		{ ATA_CMD_READ_LOG_EXT,		"READ LOG EXT" },
2302 		{ ATA_CMD_WRITE_LOG_EXT,	"WRITE LOG EXT" },
2303 		{ ATA_CMD_READ_LOG_DMA_EXT,	"READ LOG DMA EXT" },
2304 		{ ATA_CMD_WRITE_LOG_DMA_EXT, 	"WRITE LOG DMA EXT" },
2305 		{ ATA_CMD_TRUSTED_RCV,		"TRUSTED RECEIVE" },
2306 		{ ATA_CMD_TRUSTED_RCV_DMA, 	"TRUSTED RECEIVE DMA" },
2307 		{ ATA_CMD_TRUSTED_SND,		"TRUSTED SEND" },
2308 		{ ATA_CMD_TRUSTED_SND_DMA, 	"TRUSTED SEND DMA" },
2309 		{ ATA_CMD_PMP_READ,		"READ BUFFER" },
2310 		{ ATA_CMD_PMP_WRITE,		"WRITE BUFFER" },
2311 		{ ATA_CMD_CONF_OVERLAY,		"DEVICE CONFIGURATION OVERLAY" },
2312 		{ ATA_CMD_SEC_SET_PASS,		"SECURITY SET PASSWORD" },
2313 		{ ATA_CMD_SEC_UNLOCK,		"SECURITY UNLOCK" },
2314 		{ ATA_CMD_SEC_ERASE_PREP,	"SECURITY ERASE PREPARE" },
2315 		{ ATA_CMD_SEC_ERASE_UNIT,	"SECURITY ERASE UNIT" },
2316 		{ ATA_CMD_SEC_FREEZE_LOCK,	"SECURITY FREEZE LOCK" },
2317 		{ ATA_CMD_SEC_DISABLE_PASS,	"SECURITY DISABLE PASSWORD" },
2318 		{ ATA_CMD_CONFIG_STREAM,	"CONFIGURE STREAM" },
2319 		{ ATA_CMD_SMART,		"SMART" },
2320 		{ ATA_CMD_MEDIA_LOCK,		"DOOR LOCK" },
2321 		{ ATA_CMD_MEDIA_UNLOCK,		"DOOR UNLOCK" },
2322 		{ ATA_CMD_DSM,			"DATA SET MANAGEMENT" },
2323 		{ ATA_CMD_CHK_MED_CRD_TYP, 	"CHECK MEDIA CARD TYPE" },
2324 		{ ATA_CMD_CFA_REQ_EXT_ERR, 	"CFA REQUEST EXTENDED ERROR" },
2325 		{ ATA_CMD_CFA_WRITE_NE,		"CFA WRITE SECTORS WITHOUT ERASE" },
2326 		{ ATA_CMD_CFA_TRANS_SECT,	"CFA TRANSLATE SECTOR" },
2327 		{ ATA_CMD_CFA_ERASE,		"CFA ERASE SECTORS" },
2328 		{ ATA_CMD_CFA_WRITE_MULT_NE, 	"CFA WRITE MULTIPLE WITHOUT ERASE" },
2329 		{ ATA_CMD_READ_LONG,		"READ LONG (with retries)" },
2330 		{ ATA_CMD_READ_LONG_ONCE,	"READ LONG (without retries)" },
2331 		{ ATA_CMD_WRITE_LONG,		"WRITE LONG (with retries)" },
2332 		{ ATA_CMD_WRITE_LONG_ONCE,	"WRITE LONG (without retries)" },
2333 		{ ATA_CMD_RESTORE,		"RECALIBRATE" },
2334 		{ 0,				NULL } /* terminate list */
2335 	};
2336 
2337 	unsigned int i;
2338 	for (i = 0; cmd_descr[i].text; i++)
2339 		if (cmd_descr[i].command == command)
2340 			return cmd_descr[i].text;
2341 #endif
2342 
2343 	return NULL;
2344 }
2345 
2346 /**
2347  *	ata_eh_link_report - report error handling to user
2348  *	@link: ATA link EH is going on
2349  *
2350  *	Report EH to user.
2351  *
2352  *	LOCKING:
2353  *	None.
2354  */
2355 static void ata_eh_link_report(struct ata_link *link)
2356 {
2357 	struct ata_port *ap = link->ap;
2358 	struct ata_eh_context *ehc = &link->eh_context;
2359 	const char *frozen, *desc;
2360 	char tries_buf[6];
2361 	int tag, nr_failed = 0;
2362 
2363 	if (ehc->i.flags & ATA_EHI_QUIET)
2364 		return;
2365 
2366 	desc = NULL;
2367 	if (ehc->i.desc[0] != '\0')
2368 		desc = ehc->i.desc;
2369 
2370 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2371 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2372 
2373 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2374 		    ata_dev_phys_link(qc->dev) != link ||
2375 		    ((qc->flags & ATA_QCFLAG_QUIET) &&
2376 		     qc->err_mask == AC_ERR_DEV))
2377 			continue;
2378 		if (qc->flags & ATA_QCFLAG_SENSE_VALID && !qc->err_mask)
2379 			continue;
2380 
2381 		nr_failed++;
2382 	}
2383 
2384 	if (!nr_failed && !ehc->i.err_mask)
2385 		return;
2386 
2387 	frozen = "";
2388 	if (ap->pflags & ATA_PFLAG_FROZEN)
2389 		frozen = " frozen";
2390 
2391 	memset(tries_buf, 0, sizeof(tries_buf));
2392 	if (ap->eh_tries < ATA_EH_MAX_TRIES)
2393 		snprintf(tries_buf, sizeof(tries_buf) - 1, " t%d",
2394 			 ap->eh_tries);
2395 
2396 	if (ehc->i.dev) {
2397 		ata_dev_err(ehc->i.dev, "exception Emask 0x%x "
2398 			    "SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2399 			    ehc->i.err_mask, link->sactive, ehc->i.serror,
2400 			    ehc->i.action, frozen, tries_buf);
2401 		if (desc)
2402 			ata_dev_err(ehc->i.dev, "%s\n", desc);
2403 	} else {
2404 		ata_link_err(link, "exception Emask 0x%x "
2405 			     "SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2406 			     ehc->i.err_mask, link->sactive, ehc->i.serror,
2407 			     ehc->i.action, frozen, tries_buf);
2408 		if (desc)
2409 			ata_link_err(link, "%s\n", desc);
2410 	}
2411 
2412 #ifdef CONFIG_ATA_VERBOSE_ERROR
2413 	if (ehc->i.serror)
2414 		ata_link_err(link,
2415 		  "SError: { %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s}\n",
2416 		  ehc->i.serror & SERR_DATA_RECOVERED ? "RecovData " : "",
2417 		  ehc->i.serror & SERR_COMM_RECOVERED ? "RecovComm " : "",
2418 		  ehc->i.serror & SERR_DATA ? "UnrecovData " : "",
2419 		  ehc->i.serror & SERR_PERSISTENT ? "Persist " : "",
2420 		  ehc->i.serror & SERR_PROTOCOL ? "Proto " : "",
2421 		  ehc->i.serror & SERR_INTERNAL ? "HostInt " : "",
2422 		  ehc->i.serror & SERR_PHYRDY_CHG ? "PHYRdyChg " : "",
2423 		  ehc->i.serror & SERR_PHY_INT_ERR ? "PHYInt " : "",
2424 		  ehc->i.serror & SERR_COMM_WAKE ? "CommWake " : "",
2425 		  ehc->i.serror & SERR_10B_8B_ERR ? "10B8B " : "",
2426 		  ehc->i.serror & SERR_DISPARITY ? "Dispar " : "",
2427 		  ehc->i.serror & SERR_CRC ? "BadCRC " : "",
2428 		  ehc->i.serror & SERR_HANDSHAKE ? "Handshk " : "",
2429 		  ehc->i.serror & SERR_LINK_SEQ_ERR ? "LinkSeq " : "",
2430 		  ehc->i.serror & SERR_TRANS_ST_ERROR ? "TrStaTrns " : "",
2431 		  ehc->i.serror & SERR_UNRECOG_FIS ? "UnrecFIS " : "",
2432 		  ehc->i.serror & SERR_DEV_XCHG ? "DevExch " : "");
2433 #endif
2434 
2435 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2436 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2437 		struct ata_taskfile *cmd = &qc->tf, *res = &qc->result_tf;
2438 		const u8 *cdb = qc->cdb;
2439 		char data_buf[20] = "";
2440 		char cdb_buf[70] = "";
2441 
2442 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2443 		    ata_dev_phys_link(qc->dev) != link || !qc->err_mask)
2444 			continue;
2445 
2446 		if (qc->dma_dir != DMA_NONE) {
2447 			static const char *dma_str[] = {
2448 				[DMA_BIDIRECTIONAL]	= "bidi",
2449 				[DMA_TO_DEVICE]		= "out",
2450 				[DMA_FROM_DEVICE]	= "in",
2451 			};
2452 			static const char *prot_str[] = {
2453 				[ATA_PROT_PIO]		= "pio",
2454 				[ATA_PROT_DMA]		= "dma",
2455 				[ATA_PROT_NCQ]		= "ncq",
2456 				[ATAPI_PROT_PIO]	= "pio",
2457 				[ATAPI_PROT_DMA]	= "dma",
2458 			};
2459 
2460 			snprintf(data_buf, sizeof(data_buf), " %s %u %s",
2461 				 prot_str[qc->tf.protocol], qc->nbytes,
2462 				 dma_str[qc->dma_dir]);
2463 		}
2464 
2465 		if (ata_is_atapi(qc->tf.protocol)) {
2466 			if (qc->scsicmd)
2467 				scsi_print_command(qc->scsicmd);
2468 			else
2469 				snprintf(cdb_buf, sizeof(cdb_buf),
2470 				 "cdb %02x %02x %02x %02x %02x %02x %02x %02x  "
2471 				 "%02x %02x %02x %02x %02x %02x %02x %02x\n         ",
2472 				 cdb[0], cdb[1], cdb[2], cdb[3],
2473 				 cdb[4], cdb[5], cdb[6], cdb[7],
2474 				 cdb[8], cdb[9], cdb[10], cdb[11],
2475 				 cdb[12], cdb[13], cdb[14], cdb[15]);
2476 		} else {
2477 			const char *descr = ata_get_cmd_descript(cmd->command);
2478 			if (descr)
2479 				ata_dev_err(qc->dev, "failed command: %s\n",
2480 					    descr);
2481 		}
2482 
2483 		ata_dev_err(qc->dev,
2484 			"cmd %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2485 			"tag %d%s\n         %s"
2486 			"res %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2487 			"Emask 0x%x (%s)%s\n",
2488 			cmd->command, cmd->feature, cmd->nsect,
2489 			cmd->lbal, cmd->lbam, cmd->lbah,
2490 			cmd->hob_feature, cmd->hob_nsect,
2491 			cmd->hob_lbal, cmd->hob_lbam, cmd->hob_lbah,
2492 			cmd->device, qc->tag, data_buf, cdb_buf,
2493 			res->command, res->feature, res->nsect,
2494 			res->lbal, res->lbam, res->lbah,
2495 			res->hob_feature, res->hob_nsect,
2496 			res->hob_lbal, res->hob_lbam, res->hob_lbah,
2497 			res->device, qc->err_mask, ata_err_string(qc->err_mask),
2498 			qc->err_mask & AC_ERR_NCQ ? " <F>" : "");
2499 
2500 #ifdef CONFIG_ATA_VERBOSE_ERROR
2501 		if (res->command & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ |
2502 				    ATA_ERR)) {
2503 			if (res->command & ATA_BUSY)
2504 				ata_dev_err(qc->dev, "status: { Busy }\n");
2505 			else
2506 				ata_dev_err(qc->dev, "status: { %s%s%s%s}\n",
2507 				  res->command & ATA_DRDY ? "DRDY " : "",
2508 				  res->command & ATA_DF ? "DF " : "",
2509 				  res->command & ATA_DRQ ? "DRQ " : "",
2510 				  res->command & ATA_ERR ? "ERR " : "");
2511 		}
2512 
2513 		if (cmd->command != ATA_CMD_PACKET &&
2514 		    (res->feature & (ATA_ICRC | ATA_UNC | ATA_IDNF |
2515 				     ATA_ABORTED)))
2516 			ata_dev_err(qc->dev, "error: { %s%s%s%s}\n",
2517 			  res->feature & ATA_ICRC ? "ICRC " : "",
2518 			  res->feature & ATA_UNC ? "UNC " : "",
2519 			  res->feature & ATA_IDNF ? "IDNF " : "",
2520 			  res->feature & ATA_ABORTED ? "ABRT " : "");
2521 #endif
2522 	}
2523 }
2524 
2525 /**
2526  *	ata_eh_report - report error handling to user
2527  *	@ap: ATA port to report EH about
2528  *
2529  *	Report EH to user.
2530  *
2531  *	LOCKING:
2532  *	None.
2533  */
2534 void ata_eh_report(struct ata_port *ap)
2535 {
2536 	struct ata_link *link;
2537 
2538 	ata_for_each_link(link, ap, HOST_FIRST)
2539 		ata_eh_link_report(link);
2540 }
2541 
2542 static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
2543 			unsigned int *classes, unsigned long deadline,
2544 			bool clear_classes)
2545 {
2546 	struct ata_device *dev;
2547 
2548 	if (clear_classes)
2549 		ata_for_each_dev(dev, link, ALL)
2550 			classes[dev->devno] = ATA_DEV_UNKNOWN;
2551 
2552 	return reset(link, classes, deadline);
2553 }
2554 
2555 static int ata_eh_followup_srst_needed(struct ata_link *link, int rc)
2556 {
2557 	if ((link->flags & ATA_LFLAG_NO_SRST) || ata_link_offline(link))
2558 		return 0;
2559 	if (rc == -EAGAIN)
2560 		return 1;
2561 	if (sata_pmp_supported(link->ap) && ata_is_host_link(link))
2562 		return 1;
2563 	return 0;
2564 }
2565 
2566 int ata_eh_reset(struct ata_link *link, int classify,
2567 		 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
2568 		 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
2569 {
2570 	struct ata_port *ap = link->ap;
2571 	struct ata_link *slave = ap->slave_link;
2572 	struct ata_eh_context *ehc = &link->eh_context;
2573 	struct ata_eh_context *sehc = slave ? &slave->eh_context : NULL;
2574 	unsigned int *classes = ehc->classes;
2575 	unsigned int lflags = link->flags;
2576 	int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
2577 	int max_tries = 0, try = 0;
2578 	struct ata_link *failed_link;
2579 	struct ata_device *dev;
2580 	unsigned long deadline, now;
2581 	ata_reset_fn_t reset;
2582 	unsigned long flags;
2583 	u32 sstatus;
2584 	int nr_unknown, rc;
2585 
2586 	/*
2587 	 * Prepare to reset
2588 	 */
2589 	while (ata_eh_reset_timeouts[max_tries] != ULONG_MAX)
2590 		max_tries++;
2591 	if (link->flags & ATA_LFLAG_NO_HRST)
2592 		hardreset = NULL;
2593 	if (link->flags & ATA_LFLAG_NO_SRST)
2594 		softreset = NULL;
2595 
2596 	/* make sure each reset attempt is at least COOL_DOWN apart */
2597 	if (ehc->i.flags & ATA_EHI_DID_RESET) {
2598 		now = jiffies;
2599 		WARN_ON(time_after(ehc->last_reset, now));
2600 		deadline = ata_deadline(ehc->last_reset,
2601 					ATA_EH_RESET_COOL_DOWN);
2602 		if (time_before(now, deadline))
2603 			schedule_timeout_uninterruptible(deadline - now);
2604 	}
2605 
2606 	spin_lock_irqsave(ap->lock, flags);
2607 	ap->pflags |= ATA_PFLAG_RESETTING;
2608 	spin_unlock_irqrestore(ap->lock, flags);
2609 
2610 	ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
2611 
2612 	ata_for_each_dev(dev, link, ALL) {
2613 		/* If we issue an SRST then an ATA drive (not ATAPI)
2614 		 * may change configuration and be in PIO0 timing. If
2615 		 * we do a hard reset (or are coming from power on)
2616 		 * this is true for ATA or ATAPI. Until we've set a
2617 		 * suitable controller mode we should not touch the
2618 		 * bus as we may be talking too fast.
2619 		 */
2620 		dev->pio_mode = XFER_PIO_0;
2621 
2622 		/* If the controller has a pio mode setup function
2623 		 * then use it to set the chipset to rights. Don't
2624 		 * touch the DMA setup as that will be dealt with when
2625 		 * configuring devices.
2626 		 */
2627 		if (ap->ops->set_piomode)
2628 			ap->ops->set_piomode(ap, dev);
2629 	}
2630 
2631 	/* prefer hardreset */
2632 	reset = NULL;
2633 	ehc->i.action &= ~ATA_EH_RESET;
2634 	if (hardreset) {
2635 		reset = hardreset;
2636 		ehc->i.action |= ATA_EH_HARDRESET;
2637 	} else if (softreset) {
2638 		reset = softreset;
2639 		ehc->i.action |= ATA_EH_SOFTRESET;
2640 	}
2641 
2642 	if (prereset) {
2643 		unsigned long deadline = ata_deadline(jiffies,
2644 						      ATA_EH_PRERESET_TIMEOUT);
2645 
2646 		if (slave) {
2647 			sehc->i.action &= ~ATA_EH_RESET;
2648 			sehc->i.action |= ehc->i.action;
2649 		}
2650 
2651 		rc = prereset(link, deadline);
2652 
2653 		/* If present, do prereset on slave link too.  Reset
2654 		 * is skipped iff both master and slave links report
2655 		 * -ENOENT or clear ATA_EH_RESET.
2656 		 */
2657 		if (slave && (rc == 0 || rc == -ENOENT)) {
2658 			int tmp;
2659 
2660 			tmp = prereset(slave, deadline);
2661 			if (tmp != -ENOENT)
2662 				rc = tmp;
2663 
2664 			ehc->i.action |= sehc->i.action;
2665 		}
2666 
2667 		if (rc) {
2668 			if (rc == -ENOENT) {
2669 				ata_link_dbg(link, "port disabled--ignoring\n");
2670 				ehc->i.action &= ~ATA_EH_RESET;
2671 
2672 				ata_for_each_dev(dev, link, ALL)
2673 					classes[dev->devno] = ATA_DEV_NONE;
2674 
2675 				rc = 0;
2676 			} else
2677 				ata_link_err(link,
2678 					     "prereset failed (errno=%d)\n",
2679 					     rc);
2680 			goto out;
2681 		}
2682 
2683 		/* prereset() might have cleared ATA_EH_RESET.  If so,
2684 		 * bang classes, thaw and return.
2685 		 */
2686 		if (reset && !(ehc->i.action & ATA_EH_RESET)) {
2687 			ata_for_each_dev(dev, link, ALL)
2688 				classes[dev->devno] = ATA_DEV_NONE;
2689 			if ((ap->pflags & ATA_PFLAG_FROZEN) &&
2690 			    ata_is_host_link(link))
2691 				ata_eh_thaw_port(ap);
2692 			rc = 0;
2693 			goto out;
2694 		}
2695 	}
2696 
2697  retry:
2698 	/*
2699 	 * Perform reset
2700 	 */
2701 	if (ata_is_host_link(link))
2702 		ata_eh_freeze_port(ap);
2703 
2704 	deadline = ata_deadline(jiffies, ata_eh_reset_timeouts[try++]);
2705 
2706 	if (reset) {
2707 		if (verbose)
2708 			ata_link_info(link, "%s resetting link\n",
2709 				      reset == softreset ? "soft" : "hard");
2710 
2711 		/* mark that this EH session started with reset */
2712 		ehc->last_reset = jiffies;
2713 		if (reset == hardreset)
2714 			ehc->i.flags |= ATA_EHI_DID_HARDRESET;
2715 		else
2716 			ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
2717 
2718 		rc = ata_do_reset(link, reset, classes, deadline, true);
2719 		if (rc && rc != -EAGAIN) {
2720 			failed_link = link;
2721 			goto fail;
2722 		}
2723 
2724 		/* hardreset slave link if existent */
2725 		if (slave && reset == hardreset) {
2726 			int tmp;
2727 
2728 			if (verbose)
2729 				ata_link_info(slave, "hard resetting link\n");
2730 
2731 			ata_eh_about_to_do(slave, NULL, ATA_EH_RESET);
2732 			tmp = ata_do_reset(slave, reset, classes, deadline,
2733 					   false);
2734 			switch (tmp) {
2735 			case -EAGAIN:
2736 				rc = -EAGAIN;
2737 			case 0:
2738 				break;
2739 			default:
2740 				failed_link = slave;
2741 				rc = tmp;
2742 				goto fail;
2743 			}
2744 		}
2745 
2746 		/* perform follow-up SRST if necessary */
2747 		if (reset == hardreset &&
2748 		    ata_eh_followup_srst_needed(link, rc)) {
2749 			reset = softreset;
2750 
2751 			if (!reset) {
2752 				ata_link_err(link,
2753 	     "follow-up softreset required but no softreset available\n");
2754 				failed_link = link;
2755 				rc = -EINVAL;
2756 				goto fail;
2757 			}
2758 
2759 			ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
2760 			rc = ata_do_reset(link, reset, classes, deadline, true);
2761 			if (rc) {
2762 				failed_link = link;
2763 				goto fail;
2764 			}
2765 		}
2766 	} else {
2767 		if (verbose)
2768 			ata_link_info(link,
2769 	"no reset method available, skipping reset\n");
2770 		if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
2771 			lflags |= ATA_LFLAG_ASSUME_ATA;
2772 	}
2773 
2774 	/*
2775 	 * Post-reset processing
2776 	 */
2777 	ata_for_each_dev(dev, link, ALL) {
2778 		/* After the reset, the device state is PIO 0 and the
2779 		 * controller state is undefined.  Reset also wakes up
2780 		 * drives from sleeping mode.
2781 		 */
2782 		dev->pio_mode = XFER_PIO_0;
2783 		dev->flags &= ~ATA_DFLAG_SLEEPING;
2784 
2785 		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
2786 			continue;
2787 
2788 		/* apply class override */
2789 		if (lflags & ATA_LFLAG_ASSUME_ATA)
2790 			classes[dev->devno] = ATA_DEV_ATA;
2791 		else if (lflags & ATA_LFLAG_ASSUME_SEMB)
2792 			classes[dev->devno] = ATA_DEV_SEMB_UNSUP;
2793 	}
2794 
2795 	/* record current link speed */
2796 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
2797 		link->sata_spd = (sstatus >> 4) & 0xf;
2798 	if (slave && sata_scr_read(slave, SCR_STATUS, &sstatus) == 0)
2799 		slave->sata_spd = (sstatus >> 4) & 0xf;
2800 
2801 	/* thaw the port */
2802 	if (ata_is_host_link(link))
2803 		ata_eh_thaw_port(ap);
2804 
2805 	/* postreset() should clear hardware SError.  Although SError
2806 	 * is cleared during link resume, clearing SError here is
2807 	 * necessary as some PHYs raise hotplug events after SRST.
2808 	 * This introduces race condition where hotplug occurs between
2809 	 * reset and here.  This race is mediated by cross checking
2810 	 * link onlineness and classification result later.
2811 	 */
2812 	if (postreset) {
2813 		postreset(link, classes);
2814 		if (slave)
2815 			postreset(slave, classes);
2816 	}
2817 
2818 	/*
2819 	 * Some controllers can't be frozen very well and may set spurious
2820 	 * error conditions during reset.  Clear accumulated error
2821 	 * information and re-thaw the port if frozen.  As reset is the
2822 	 * final recovery action and we cross check link onlineness against
2823 	 * device classification later, no hotplug event is lost by this.
2824 	 */
2825 	spin_lock_irqsave(link->ap->lock, flags);
2826 	memset(&link->eh_info, 0, sizeof(link->eh_info));
2827 	if (slave)
2828 		memset(&slave->eh_info, 0, sizeof(link->eh_info));
2829 	ap->pflags &= ~ATA_PFLAG_EH_PENDING;
2830 	spin_unlock_irqrestore(link->ap->lock, flags);
2831 
2832 	if (ap->pflags & ATA_PFLAG_FROZEN)
2833 		ata_eh_thaw_port(ap);
2834 
2835 	/*
2836 	 * Make sure onlineness and classification result correspond.
2837 	 * Hotplug could have happened during reset and some
2838 	 * controllers fail to wait while a drive is spinning up after
2839 	 * being hotplugged causing misdetection.  By cross checking
2840 	 * link on/offlineness and classification result, those
2841 	 * conditions can be reliably detected and retried.
2842 	 */
2843 	nr_unknown = 0;
2844 	ata_for_each_dev(dev, link, ALL) {
2845 		if (ata_phys_link_online(ata_dev_phys_link(dev))) {
2846 			if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
2847 				ata_dev_dbg(dev, "link online but device misclassified\n");
2848 				classes[dev->devno] = ATA_DEV_NONE;
2849 				nr_unknown++;
2850 			}
2851 		} else if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
2852 			if (ata_class_enabled(classes[dev->devno]))
2853 				ata_dev_dbg(dev,
2854 					    "link offline, clearing class %d to NONE\n",
2855 					    classes[dev->devno]);
2856 			classes[dev->devno] = ATA_DEV_NONE;
2857 		} else if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
2858 			ata_dev_dbg(dev,
2859 				    "link status unknown, clearing UNKNOWN to NONE\n");
2860 			classes[dev->devno] = ATA_DEV_NONE;
2861 		}
2862 	}
2863 
2864 	if (classify && nr_unknown) {
2865 		if (try < max_tries) {
2866 			ata_link_warn(link,
2867 				      "link online but %d devices misclassified, retrying\n",
2868 				      nr_unknown);
2869 			failed_link = link;
2870 			rc = -EAGAIN;
2871 			goto fail;
2872 		}
2873 		ata_link_warn(link,
2874 			      "link online but %d devices misclassified, "
2875 			      "device detection might fail\n", nr_unknown);
2876 	}
2877 
2878 	/* reset successful, schedule revalidation */
2879 	ata_eh_done(link, NULL, ATA_EH_RESET);
2880 	if (slave)
2881 		ata_eh_done(slave, NULL, ATA_EH_RESET);
2882 	ehc->last_reset = jiffies;		/* update to completion time */
2883 	ehc->i.action |= ATA_EH_REVALIDATE;
2884 	link->lpm_policy = ATA_LPM_UNKNOWN;	/* reset LPM state */
2885 
2886 	rc = 0;
2887  out:
2888 	/* clear hotplug flag */
2889 	ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2890 	if (slave)
2891 		sehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2892 
2893 	spin_lock_irqsave(ap->lock, flags);
2894 	ap->pflags &= ~ATA_PFLAG_RESETTING;
2895 	spin_unlock_irqrestore(ap->lock, flags);
2896 
2897 	return rc;
2898 
2899  fail:
2900 	/* if SCR isn't accessible on a fan-out port, PMP needs to be reset */
2901 	if (!ata_is_host_link(link) &&
2902 	    sata_scr_read(link, SCR_STATUS, &sstatus))
2903 		rc = -ERESTART;
2904 
2905 	if (try >= max_tries) {
2906 		/*
2907 		 * Thaw host port even if reset failed, so that the port
2908 		 * can be retried on the next phy event.  This risks
2909 		 * repeated EH runs but seems to be a better tradeoff than
2910 		 * shutting down a port after a botched hotplug attempt.
2911 		 */
2912 		if (ata_is_host_link(link))
2913 			ata_eh_thaw_port(ap);
2914 		goto out;
2915 	}
2916 
2917 	now = jiffies;
2918 	if (time_before(now, deadline)) {
2919 		unsigned long delta = deadline - now;
2920 
2921 		ata_link_warn(failed_link,
2922 			"reset failed (errno=%d), retrying in %u secs\n",
2923 			rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000));
2924 
2925 		ata_eh_release(ap);
2926 		while (delta)
2927 			delta = schedule_timeout_uninterruptible(delta);
2928 		ata_eh_acquire(ap);
2929 	}
2930 
2931 	/*
2932 	 * While disks spinup behind PMP, some controllers fail sending SRST.
2933 	 * They need to be reset - as well as the PMP - before retrying.
2934 	 */
2935 	if (rc == -ERESTART) {
2936 		if (ata_is_host_link(link))
2937 			ata_eh_thaw_port(ap);
2938 		goto out;
2939 	}
2940 
2941 	if (try == max_tries - 1) {
2942 		sata_down_spd_limit(link, 0);
2943 		if (slave)
2944 			sata_down_spd_limit(slave, 0);
2945 	} else if (rc == -EPIPE)
2946 		sata_down_spd_limit(failed_link, 0);
2947 
2948 	if (hardreset)
2949 		reset = hardreset;
2950 	goto retry;
2951 }
2952 
2953 static inline void ata_eh_pull_park_action(struct ata_port *ap)
2954 {
2955 	struct ata_link *link;
2956 	struct ata_device *dev;
2957 	unsigned long flags;
2958 
2959 	/*
2960 	 * This function can be thought of as an extended version of
2961 	 * ata_eh_about_to_do() specially crafted to accommodate the
2962 	 * requirements of ATA_EH_PARK handling. Since the EH thread
2963 	 * does not leave the do {} while () loop in ata_eh_recover as
2964 	 * long as the timeout for a park request to *one* device on
2965 	 * the port has not expired, and since we still want to pick
2966 	 * up park requests to other devices on the same port or
2967 	 * timeout updates for the same device, we have to pull
2968 	 * ATA_EH_PARK actions from eh_info into eh_context.i
2969 	 * ourselves at the beginning of each pass over the loop.
2970 	 *
2971 	 * Additionally, all write accesses to &ap->park_req_pending
2972 	 * through INIT_COMPLETION() (see below) or complete_all()
2973 	 * (see ata_scsi_park_store()) are protected by the host lock.
2974 	 * As a result we have that park_req_pending.done is zero on
2975 	 * exit from this function, i.e. when ATA_EH_PARK actions for
2976 	 * *all* devices on port ap have been pulled into the
2977 	 * respective eh_context structs. If, and only if,
2978 	 * park_req_pending.done is non-zero by the time we reach
2979 	 * wait_for_completion_timeout(), another ATA_EH_PARK action
2980 	 * has been scheduled for at least one of the devices on port
2981 	 * ap and we have to cycle over the do {} while () loop in
2982 	 * ata_eh_recover() again.
2983 	 */
2984 
2985 	spin_lock_irqsave(ap->lock, flags);
2986 	INIT_COMPLETION(ap->park_req_pending);
2987 	ata_for_each_link(link, ap, EDGE) {
2988 		ata_for_each_dev(dev, link, ALL) {
2989 			struct ata_eh_info *ehi = &link->eh_info;
2990 
2991 			link->eh_context.i.dev_action[dev->devno] |=
2992 				ehi->dev_action[dev->devno] & ATA_EH_PARK;
2993 			ata_eh_clear_action(link, dev, ehi, ATA_EH_PARK);
2994 		}
2995 	}
2996 	spin_unlock_irqrestore(ap->lock, flags);
2997 }
2998 
2999 static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
3000 {
3001 	struct ata_eh_context *ehc = &dev->link->eh_context;
3002 	struct ata_taskfile tf;
3003 	unsigned int err_mask;
3004 
3005 	ata_tf_init(dev, &tf);
3006 	if (park) {
3007 		ehc->unloaded_mask |= 1 << dev->devno;
3008 		tf.command = ATA_CMD_IDLEIMMEDIATE;
3009 		tf.feature = 0x44;
3010 		tf.lbal = 0x4c;
3011 		tf.lbam = 0x4e;
3012 		tf.lbah = 0x55;
3013 	} else {
3014 		ehc->unloaded_mask &= ~(1 << dev->devno);
3015 		tf.command = ATA_CMD_CHK_POWER;
3016 	}
3017 
3018 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
3019 	tf.protocol |= ATA_PROT_NODATA;
3020 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
3021 	if (park && (err_mask || tf.lbal != 0xc4)) {
3022 		ata_dev_err(dev, "head unload failed!\n");
3023 		ehc->unloaded_mask &= ~(1 << dev->devno);
3024 	}
3025 }
3026 
3027 static int ata_eh_revalidate_and_attach(struct ata_link *link,
3028 					struct ata_device **r_failed_dev)
3029 {
3030 	struct ata_port *ap = link->ap;
3031 	struct ata_eh_context *ehc = &link->eh_context;
3032 	struct ata_device *dev;
3033 	unsigned int new_mask = 0;
3034 	unsigned long flags;
3035 	int rc = 0;
3036 
3037 	DPRINTK("ENTER\n");
3038 
3039 	/* For PATA drive side cable detection to work, IDENTIFY must
3040 	 * be done backwards such that PDIAG- is released by the slave
3041 	 * device before the master device is identified.
3042 	 */
3043 	ata_for_each_dev(dev, link, ALL_REVERSE) {
3044 		unsigned int action = ata_eh_dev_action(dev);
3045 		unsigned int readid_flags = 0;
3046 
3047 		if (ehc->i.flags & ATA_EHI_DID_RESET)
3048 			readid_flags |= ATA_READID_POSTRESET;
3049 
3050 		if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
3051 			WARN_ON(dev->class == ATA_DEV_PMP);
3052 
3053 			if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
3054 				rc = -EIO;
3055 				goto err;
3056 			}
3057 
3058 			ata_eh_about_to_do(link, dev, ATA_EH_REVALIDATE);
3059 			rc = ata_dev_revalidate(dev, ehc->classes[dev->devno],
3060 						readid_flags);
3061 			if (rc)
3062 				goto err;
3063 
3064 			ata_eh_done(link, dev, ATA_EH_REVALIDATE);
3065 
3066 			/* Configuration may have changed, reconfigure
3067 			 * transfer mode.
3068 			 */
3069 			ehc->i.flags |= ATA_EHI_SETMODE;
3070 
3071 			/* schedule the scsi_rescan_device() here */
3072 			schedule_work(&(ap->scsi_rescan_task));
3073 		} else if (dev->class == ATA_DEV_UNKNOWN &&
3074 			   ehc->tries[dev->devno] &&
3075 			   ata_class_enabled(ehc->classes[dev->devno])) {
3076 			/* Temporarily set dev->class, it will be
3077 			 * permanently set once all configurations are
3078 			 * complete.  This is necessary because new
3079 			 * device configuration is done in two
3080 			 * separate loops.
3081 			 */
3082 			dev->class = ehc->classes[dev->devno];
3083 
3084 			if (dev->class == ATA_DEV_PMP)
3085 				rc = sata_pmp_attach(dev);
3086 			else
3087 				rc = ata_dev_read_id(dev, &dev->class,
3088 						     readid_flags, dev->id);
3089 
3090 			/* read_id might have changed class, store and reset */
3091 			ehc->classes[dev->devno] = dev->class;
3092 			dev->class = ATA_DEV_UNKNOWN;
3093 
3094 			switch (rc) {
3095 			case 0:
3096 				/* clear error info accumulated during probe */
3097 				ata_ering_clear(&dev->ering);
3098 				new_mask |= 1 << dev->devno;
3099 				break;
3100 			case -ENOENT:
3101 				/* IDENTIFY was issued to non-existent
3102 				 * device.  No need to reset.  Just
3103 				 * thaw and ignore the device.
3104 				 */
3105 				ata_eh_thaw_port(ap);
3106 				break;
3107 			default:
3108 				goto err;
3109 			}
3110 		}
3111 	}
3112 
3113 	/* PDIAG- should have been released, ask cable type if post-reset */
3114 	if ((ehc->i.flags & ATA_EHI_DID_RESET) && ata_is_host_link(link)) {
3115 		if (ap->ops->cable_detect)
3116 			ap->cbl = ap->ops->cable_detect(ap);
3117 		ata_force_cbl(ap);
3118 	}
3119 
3120 	/* Configure new devices forward such that user doesn't see
3121 	 * device detection messages backwards.
3122 	 */
3123 	ata_for_each_dev(dev, link, ALL) {
3124 		if (!(new_mask & (1 << dev->devno)))
3125 			continue;
3126 
3127 		dev->class = ehc->classes[dev->devno];
3128 
3129 		if (dev->class == ATA_DEV_PMP)
3130 			continue;
3131 
3132 		ehc->i.flags |= ATA_EHI_PRINTINFO;
3133 		rc = ata_dev_configure(dev);
3134 		ehc->i.flags &= ~ATA_EHI_PRINTINFO;
3135 		if (rc) {
3136 			dev->class = ATA_DEV_UNKNOWN;
3137 			goto err;
3138 		}
3139 
3140 		spin_lock_irqsave(ap->lock, flags);
3141 		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
3142 		spin_unlock_irqrestore(ap->lock, flags);
3143 
3144 		/* new device discovered, configure xfermode */
3145 		ehc->i.flags |= ATA_EHI_SETMODE;
3146 	}
3147 
3148 	return 0;
3149 
3150  err:
3151 	*r_failed_dev = dev;
3152 	DPRINTK("EXIT rc=%d\n", rc);
3153 	return rc;
3154 }
3155 
3156 /**
3157  *	ata_set_mode - Program timings and issue SET FEATURES - XFER
3158  *	@link: link on which timings will be programmed
3159  *	@r_failed_dev: out parameter for failed device
3160  *
3161  *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3162  *	ata_set_mode() fails, pointer to the failing device is
3163  *	returned in @r_failed_dev.
3164  *
3165  *	LOCKING:
3166  *	PCI/etc. bus probe sem.
3167  *
3168  *	RETURNS:
3169  *	0 on success, negative errno otherwise
3170  */
3171 int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3172 {
3173 	struct ata_port *ap = link->ap;
3174 	struct ata_device *dev;
3175 	int rc;
3176 
3177 	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
3178 	ata_for_each_dev(dev, link, ENABLED) {
3179 		if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
3180 			struct ata_ering_entry *ent;
3181 
3182 			ent = ata_ering_top(&dev->ering);
3183 			if (ent)
3184 				ent->eflags &= ~ATA_EFLAG_DUBIOUS_XFER;
3185 		}
3186 	}
3187 
3188 	/* has private set_mode? */
3189 	if (ap->ops->set_mode)
3190 		rc = ap->ops->set_mode(link, r_failed_dev);
3191 	else
3192 		rc = ata_do_set_mode(link, r_failed_dev);
3193 
3194 	/* if transfer mode has changed, set DUBIOUS_XFER on device */
3195 	ata_for_each_dev(dev, link, ENABLED) {
3196 		struct ata_eh_context *ehc = &link->eh_context;
3197 		u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
3198 		u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));
3199 
3200 		if (dev->xfer_mode != saved_xfer_mode ||
3201 		    ata_ncq_enabled(dev) != saved_ncq)
3202 			dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
3203 	}
3204 
3205 	return rc;
3206 }
3207 
3208 /**
3209  *	atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
3210  *	@dev: ATAPI device to clear UA for
3211  *
3212  *	Resets and other operations can make an ATAPI device raise
3213  *	UNIT ATTENTION which causes the next operation to fail.  This
3214  *	function clears UA.
3215  *
3216  *	LOCKING:
3217  *	EH context (may sleep).
3218  *
3219  *	RETURNS:
3220  *	0 on success, -errno on failure.
3221  */
3222 static int atapi_eh_clear_ua(struct ata_device *dev)
3223 {
3224 	int i;
3225 
3226 	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
3227 		u8 *sense_buffer = dev->link->ap->sector_buf;
3228 		u8 sense_key = 0;
3229 		unsigned int err_mask;
3230 
3231 		err_mask = atapi_eh_tur(dev, &sense_key);
3232 		if (err_mask != 0 && err_mask != AC_ERR_DEV) {
3233 			ata_dev_warn(dev,
3234 				     "TEST_UNIT_READY failed (err_mask=0x%x)\n",
3235 				     err_mask);
3236 			return -EIO;
3237 		}
3238 
3239 		if (!err_mask || sense_key != UNIT_ATTENTION)
3240 			return 0;
3241 
3242 		err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
3243 		if (err_mask) {
3244 			ata_dev_warn(dev, "failed to clear "
3245 				"UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
3246 			return -EIO;
3247 		}
3248 	}
3249 
3250 	ata_dev_warn(dev, "UNIT ATTENTION persists after %d tries\n",
3251 		     ATA_EH_UA_TRIES);
3252 
3253 	return 0;
3254 }
3255 
3256 /**
3257  *	ata_eh_maybe_retry_flush - Retry FLUSH if necessary
3258  *	@dev: ATA device which may need FLUSH retry
3259  *
3260  *	If @dev failed FLUSH, it needs to be reported upper layer
3261  *	immediately as it means that @dev failed to remap and already
3262  *	lost at least a sector and further FLUSH retrials won't make
3263  *	any difference to the lost sector.  However, if FLUSH failed
3264  *	for other reasons, for example transmission error, FLUSH needs
3265  *	to be retried.
3266  *
3267  *	This function determines whether FLUSH failure retry is
3268  *	necessary and performs it if so.
3269  *
3270  *	RETURNS:
3271  *	0 if EH can continue, -errno if EH needs to be repeated.
3272  */
3273 static int ata_eh_maybe_retry_flush(struct ata_device *dev)
3274 {
3275 	struct ata_link *link = dev->link;
3276 	struct ata_port *ap = link->ap;
3277 	struct ata_queued_cmd *qc;
3278 	struct ata_taskfile tf;
3279 	unsigned int err_mask;
3280 	int rc = 0;
3281 
3282 	/* did flush fail for this device? */
3283 	if (!ata_tag_valid(link->active_tag))
3284 		return 0;
3285 
3286 	qc = __ata_qc_from_tag(ap, link->active_tag);
3287 	if (qc->dev != dev || (qc->tf.command != ATA_CMD_FLUSH_EXT &&
3288 			       qc->tf.command != ATA_CMD_FLUSH))
3289 		return 0;
3290 
3291 	/* if the device failed it, it should be reported to upper layers */
3292 	if (qc->err_mask & AC_ERR_DEV)
3293 		return 0;
3294 
3295 	/* flush failed for some other reason, give it another shot */
3296 	ata_tf_init(dev, &tf);
3297 
3298 	tf.command = qc->tf.command;
3299 	tf.flags |= ATA_TFLAG_DEVICE;
3300 	tf.protocol = ATA_PROT_NODATA;
3301 
3302 	ata_dev_warn(dev, "retrying FLUSH 0x%x Emask 0x%x\n",
3303 		       tf.command, qc->err_mask);
3304 
3305 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
3306 	if (!err_mask) {
3307 		/*
3308 		 * FLUSH is complete but there's no way to
3309 		 * successfully complete a failed command from EH.
3310 		 * Making sure retry is allowed at least once and
3311 		 * retrying it should do the trick - whatever was in
3312 		 * the cache is already on the platter and this won't
3313 		 * cause infinite loop.
3314 		 */
3315 		qc->scsicmd->allowed = max(qc->scsicmd->allowed, 1);
3316 	} else {
3317 		ata_dev_warn(dev, "FLUSH failed Emask 0x%x\n",
3318 			       err_mask);
3319 		rc = -EIO;
3320 
3321 		/* if device failed it, report it to upper layers */
3322 		if (err_mask & AC_ERR_DEV) {
3323 			qc->err_mask |= AC_ERR_DEV;
3324 			qc->result_tf = tf;
3325 			if (!(ap->pflags & ATA_PFLAG_FROZEN))
3326 				rc = 0;
3327 		}
3328 	}
3329 	return rc;
3330 }
3331 
3332 /**
3333  *	ata_eh_set_lpm - configure SATA interface power management
3334  *	@link: link to configure power management
3335  *	@policy: the link power management policy
3336  *	@r_failed_dev: out parameter for failed device
3337  *
3338  *	Enable SATA Interface power management.  This will enable
3339  *	Device Interface Power Management (DIPM) for min_power
3340  * 	policy, and then call driver specific callbacks for
3341  *	enabling Host Initiated Power management.
3342  *
3343  *	LOCKING:
3344  *	EH context.
3345  *
3346  *	RETURNS:
3347  *	0 on success, -errno on failure.
3348  */
3349 static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
3350 			  struct ata_device **r_failed_dev)
3351 {
3352 	struct ata_port *ap = ata_is_host_link(link) ? link->ap : NULL;
3353 	struct ata_eh_context *ehc = &link->eh_context;
3354 	struct ata_device *dev, *link_dev = NULL, *lpm_dev = NULL;
3355 	enum ata_lpm_policy old_policy = link->lpm_policy;
3356 	bool no_dipm = link->ap->flags & ATA_FLAG_NO_DIPM;
3357 	unsigned int hints = ATA_LPM_EMPTY | ATA_LPM_HIPM;
3358 	unsigned int err_mask;
3359 	int rc;
3360 
3361 	/* if the link or host doesn't do LPM, noop */
3362 	if ((link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
3363 		return 0;
3364 
3365 	/*
3366 	 * DIPM is enabled only for MIN_POWER as some devices
3367 	 * misbehave when the host NACKs transition to SLUMBER.  Order
3368 	 * device and link configurations such that the host always
3369 	 * allows DIPM requests.
3370 	 */
3371 	ata_for_each_dev(dev, link, ENABLED) {
3372 		bool hipm = ata_id_has_hipm(dev->id);
3373 		bool dipm = ata_id_has_dipm(dev->id) && !no_dipm;
3374 
3375 		/* find the first enabled and LPM enabled devices */
3376 		if (!link_dev)
3377 			link_dev = dev;
3378 
3379 		if (!lpm_dev && (hipm || dipm))
3380 			lpm_dev = dev;
3381 
3382 		hints &= ~ATA_LPM_EMPTY;
3383 		if (!hipm)
3384 			hints &= ~ATA_LPM_HIPM;
3385 
3386 		/* disable DIPM before changing link config */
3387 		if (policy != ATA_LPM_MIN_POWER && dipm) {
3388 			err_mask = ata_dev_set_feature(dev,
3389 					SETFEATURES_SATA_DISABLE, SATA_DIPM);
3390 			if (err_mask && err_mask != AC_ERR_DEV) {
3391 				ata_dev_warn(dev,
3392 					     "failed to disable DIPM, Emask 0x%x\n",
3393 					     err_mask);
3394 				rc = -EIO;
3395 				goto fail;
3396 			}
3397 		}
3398 	}
3399 
3400 	if (ap) {
3401 		rc = ap->ops->set_lpm(link, policy, hints);
3402 		if (!rc && ap->slave_link)
3403 			rc = ap->ops->set_lpm(ap->slave_link, policy, hints);
3404 	} else
3405 		rc = sata_pmp_set_lpm(link, policy, hints);
3406 
3407 	/*
3408 	 * Attribute link config failure to the first (LPM) enabled
3409 	 * device on the link.
3410 	 */
3411 	if (rc) {
3412 		if (rc == -EOPNOTSUPP) {
3413 			link->flags |= ATA_LFLAG_NO_LPM;
3414 			return 0;
3415 		}
3416 		dev = lpm_dev ? lpm_dev : link_dev;
3417 		goto fail;
3418 	}
3419 
3420 	/*
3421 	 * Low level driver acked the transition.  Issue DIPM command
3422 	 * with the new policy set.
3423 	 */
3424 	link->lpm_policy = policy;
3425 	if (ap && ap->slave_link)
3426 		ap->slave_link->lpm_policy = policy;
3427 
3428 	/* host config updated, enable DIPM if transitioning to MIN_POWER */
3429 	ata_for_each_dev(dev, link, ENABLED) {
3430 		if (policy == ATA_LPM_MIN_POWER && !no_dipm &&
3431 		    ata_id_has_dipm(dev->id)) {
3432 			err_mask = ata_dev_set_feature(dev,
3433 					SETFEATURES_SATA_ENABLE, SATA_DIPM);
3434 			if (err_mask && err_mask != AC_ERR_DEV) {
3435 				ata_dev_warn(dev,
3436 					"failed to enable DIPM, Emask 0x%x\n",
3437 					err_mask);
3438 				rc = -EIO;
3439 				goto fail;
3440 			}
3441 		}
3442 	}
3443 
3444 	return 0;
3445 
3446 fail:
3447 	/* restore the old policy */
3448 	link->lpm_policy = old_policy;
3449 	if (ap && ap->slave_link)
3450 		ap->slave_link->lpm_policy = old_policy;
3451 
3452 	/* if no device or only one more chance is left, disable LPM */
3453 	if (!dev || ehc->tries[dev->devno] <= 2) {
3454 		ata_link_warn(link, "disabling LPM on the link\n");
3455 		link->flags |= ATA_LFLAG_NO_LPM;
3456 	}
3457 	if (r_failed_dev)
3458 		*r_failed_dev = dev;
3459 	return rc;
3460 }
3461 
3462 int ata_link_nr_enabled(struct ata_link *link)
3463 {
3464 	struct ata_device *dev;
3465 	int cnt = 0;
3466 
3467 	ata_for_each_dev(dev, link, ENABLED)
3468 		cnt++;
3469 	return cnt;
3470 }
3471 
3472 static int ata_link_nr_vacant(struct ata_link *link)
3473 {
3474 	struct ata_device *dev;
3475 	int cnt = 0;
3476 
3477 	ata_for_each_dev(dev, link, ALL)
3478 		if (dev->class == ATA_DEV_UNKNOWN)
3479 			cnt++;
3480 	return cnt;
3481 }
3482 
3483 static int ata_eh_skip_recovery(struct ata_link *link)
3484 {
3485 	struct ata_port *ap = link->ap;
3486 	struct ata_eh_context *ehc = &link->eh_context;
3487 	struct ata_device *dev;
3488 
3489 	/* skip disabled links */
3490 	if (link->flags & ATA_LFLAG_DISABLED)
3491 		return 1;
3492 
3493 	/* skip if explicitly requested */
3494 	if (ehc->i.flags & ATA_EHI_NO_RECOVERY)
3495 		return 1;
3496 
3497 	/* thaw frozen port and recover failed devices */
3498 	if ((ap->pflags & ATA_PFLAG_FROZEN) || ata_link_nr_enabled(link))
3499 		return 0;
3500 
3501 	/* reset at least once if reset is requested */
3502 	if ((ehc->i.action & ATA_EH_RESET) &&
3503 	    !(ehc->i.flags & ATA_EHI_DID_RESET))
3504 		return 0;
3505 
3506 	/* skip if class codes for all vacant slots are ATA_DEV_NONE */
3507 	ata_for_each_dev(dev, link, ALL) {
3508 		if (dev->class == ATA_DEV_UNKNOWN &&
3509 		    ehc->classes[dev->devno] != ATA_DEV_NONE)
3510 			return 0;
3511 	}
3512 
3513 	return 1;
3514 }
3515 
3516 static int ata_count_probe_trials_cb(struct ata_ering_entry *ent, void *void_arg)
3517 {
3518 	u64 interval = msecs_to_jiffies(ATA_EH_PROBE_TRIAL_INTERVAL);
3519 	u64 now = get_jiffies_64();
3520 	int *trials = void_arg;
3521 
3522 	if ((ent->eflags & ATA_EFLAG_OLD_ER) ||
3523 	    (ent->timestamp < now - min(now, interval)))
3524 		return -1;
3525 
3526 	(*trials)++;
3527 	return 0;
3528 }
3529 
3530 static int ata_eh_schedule_probe(struct ata_device *dev)
3531 {
3532 	struct ata_eh_context *ehc = &dev->link->eh_context;
3533 	struct ata_link *link = ata_dev_phys_link(dev);
3534 	int trials = 0;
3535 
3536 	if (!(ehc->i.probe_mask & (1 << dev->devno)) ||
3537 	    (ehc->did_probe_mask & (1 << dev->devno)))
3538 		return 0;
3539 
3540 	ata_eh_detach_dev(dev);
3541 	ata_dev_init(dev);
3542 	ehc->did_probe_mask |= (1 << dev->devno);
3543 	ehc->i.action |= ATA_EH_RESET;
3544 	ehc->saved_xfer_mode[dev->devno] = 0;
3545 	ehc->saved_ncq_enabled &= ~(1 << dev->devno);
3546 
3547 	/* the link maybe in a deep sleep, wake it up */
3548 	if (link->lpm_policy > ATA_LPM_MAX_POWER) {
3549 		if (ata_is_host_link(link))
3550 			link->ap->ops->set_lpm(link, ATA_LPM_MAX_POWER,
3551 					       ATA_LPM_EMPTY);
3552 		else
3553 			sata_pmp_set_lpm(link, ATA_LPM_MAX_POWER,
3554 					 ATA_LPM_EMPTY);
3555 	}
3556 
3557 	/* Record and count probe trials on the ering.  The specific
3558 	 * error mask used is irrelevant.  Because a successful device
3559 	 * detection clears the ering, this count accumulates only if
3560 	 * there are consecutive failed probes.
3561 	 *
3562 	 * If the count is equal to or higher than ATA_EH_PROBE_TRIALS
3563 	 * in the last ATA_EH_PROBE_TRIAL_INTERVAL, link speed is
3564 	 * forced to 1.5Gbps.
3565 	 *
3566 	 * This is to work around cases where failed link speed
3567 	 * negotiation results in device misdetection leading to
3568 	 * infinite DEVXCHG or PHRDY CHG events.
3569 	 */
3570 	ata_ering_record(&dev->ering, 0, AC_ERR_OTHER);
3571 	ata_ering_map(&dev->ering, ata_count_probe_trials_cb, &trials);
3572 
3573 	if (trials > ATA_EH_PROBE_TRIALS)
3574 		sata_down_spd_limit(link, 1);
3575 
3576 	return 1;
3577 }
3578 
3579 static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
3580 {
3581 	struct ata_eh_context *ehc = &dev->link->eh_context;
3582 
3583 	/* -EAGAIN from EH routine indicates retry without prejudice.
3584 	 * The requester is responsible for ensuring forward progress.
3585 	 */
3586 	if (err != -EAGAIN)
3587 		ehc->tries[dev->devno]--;
3588 
3589 	switch (err) {
3590 	case -ENODEV:
3591 		/* device missing or wrong IDENTIFY data, schedule probing */
3592 		ehc->i.probe_mask |= (1 << dev->devno);
3593 	case -EINVAL:
3594 		/* give it just one more chance */
3595 		ehc->tries[dev->devno] = min(ehc->tries[dev->devno], 1);
3596 	case -EIO:
3597 		if (ehc->tries[dev->devno] == 1) {
3598 			/* This is the last chance, better to slow
3599 			 * down than lose it.
3600 			 */
3601 			sata_down_spd_limit(ata_dev_phys_link(dev), 0);
3602 			if (dev->pio_mode > XFER_PIO_0)
3603 				ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
3604 		}
3605 	}
3606 
3607 	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) {
3608 		/* disable device if it has used up all its chances */
3609 		ata_dev_disable(dev);
3610 
3611 		/* detach if offline */
3612 		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
3613 			ata_eh_detach_dev(dev);
3614 
3615 		/* schedule probe if necessary */
3616 		if (ata_eh_schedule_probe(dev)) {
3617 			ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
3618 			memset(ehc->cmd_timeout_idx[dev->devno], 0,
3619 			       sizeof(ehc->cmd_timeout_idx[dev->devno]));
3620 		}
3621 
3622 		return 1;
3623 	} else {
3624 		ehc->i.action |= ATA_EH_RESET;
3625 		return 0;
3626 	}
3627 }
3628 
3629 /**
3630  *	ata_eh_recover - recover host port after error
3631  *	@ap: host port to recover
3632  *	@prereset: prereset method (can be NULL)
3633  *	@softreset: softreset method (can be NULL)
3634  *	@hardreset: hardreset method (can be NULL)
3635  *	@postreset: postreset method (can be NULL)
3636  *	@r_failed_link: out parameter for failed link
3637  *
3638  *	This is the alpha and omega, eum and yang, heart and soul of
3639  *	libata exception handling.  On entry, actions required to
3640  *	recover each link and hotplug requests are recorded in the
3641  *	link's eh_context.  This function executes all the operations
3642  *	with appropriate retrials and fallbacks to resurrect failed
3643  *	devices, detach goners and greet newcomers.
3644  *
3645  *	LOCKING:
3646  *	Kernel thread context (may sleep).
3647  *
3648  *	RETURNS:
3649  *	0 on success, -errno on failure.
3650  */
3651 int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
3652 		   ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3653 		   ata_postreset_fn_t postreset,
3654 		   struct ata_link **r_failed_link)
3655 {
3656 	struct ata_link *link;
3657 	struct ata_device *dev;
3658 	int rc, nr_fails;
3659 	unsigned long flags, deadline;
3660 
3661 	DPRINTK("ENTER\n");
3662 
3663 	/* prep for recovery */
3664 	ata_for_each_link(link, ap, EDGE) {
3665 		struct ata_eh_context *ehc = &link->eh_context;
3666 
3667 		/* re-enable link? */
3668 		if (ehc->i.action & ATA_EH_ENABLE_LINK) {
3669 			ata_eh_about_to_do(link, NULL, ATA_EH_ENABLE_LINK);
3670 			spin_lock_irqsave(ap->lock, flags);
3671 			link->flags &= ~ATA_LFLAG_DISABLED;
3672 			spin_unlock_irqrestore(ap->lock, flags);
3673 			ata_eh_done(link, NULL, ATA_EH_ENABLE_LINK);
3674 		}
3675 
3676 		ata_for_each_dev(dev, link, ALL) {
3677 			if (link->flags & ATA_LFLAG_NO_RETRY)
3678 				ehc->tries[dev->devno] = 1;
3679 			else
3680 				ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
3681 
3682 			/* collect port action mask recorded in dev actions */
3683 			ehc->i.action |= ehc->i.dev_action[dev->devno] &
3684 					 ~ATA_EH_PERDEV_MASK;
3685 			ehc->i.dev_action[dev->devno] &= ATA_EH_PERDEV_MASK;
3686 
3687 			/* process hotplug request */
3688 			if (dev->flags & ATA_DFLAG_DETACH)
3689 				ata_eh_detach_dev(dev);
3690 
3691 			/* schedule probe if necessary */
3692 			if (!ata_dev_enabled(dev))
3693 				ata_eh_schedule_probe(dev);
3694 		}
3695 	}
3696 
3697  retry:
3698 	rc = 0;
3699 
3700 	/* if UNLOADING, finish immediately */
3701 	if (ap->pflags & ATA_PFLAG_UNLOADING)
3702 		goto out;
3703 
3704 	/* prep for EH */
3705 	ata_for_each_link(link, ap, EDGE) {
3706 		struct ata_eh_context *ehc = &link->eh_context;
3707 
3708 		/* skip EH if possible. */
3709 		if (ata_eh_skip_recovery(link))
3710 			ehc->i.action = 0;
3711 
3712 		ata_for_each_dev(dev, link, ALL)
3713 			ehc->classes[dev->devno] = ATA_DEV_UNKNOWN;
3714 	}
3715 
3716 	/* reset */
3717 	ata_for_each_link(link, ap, EDGE) {
3718 		struct ata_eh_context *ehc = &link->eh_context;
3719 
3720 		if (!(ehc->i.action & ATA_EH_RESET))
3721 			continue;
3722 
3723 		rc = ata_eh_reset(link, ata_link_nr_vacant(link),
3724 				  prereset, softreset, hardreset, postreset);
3725 		if (rc) {
3726 			ata_link_err(link, "reset failed, giving up\n");
3727 			goto out;
3728 		}
3729 	}
3730 
3731 	do {
3732 		unsigned long now;
3733 
3734 		/*
3735 		 * clears ATA_EH_PARK in eh_info and resets
3736 		 * ap->park_req_pending
3737 		 */
3738 		ata_eh_pull_park_action(ap);
3739 
3740 		deadline = jiffies;
3741 		ata_for_each_link(link, ap, EDGE) {
3742 			ata_for_each_dev(dev, link, ALL) {
3743 				struct ata_eh_context *ehc = &link->eh_context;
3744 				unsigned long tmp;
3745 
3746 				if (dev->class != ATA_DEV_ATA)
3747 					continue;
3748 				if (!(ehc->i.dev_action[dev->devno] &
3749 				      ATA_EH_PARK))
3750 					continue;
3751 				tmp = dev->unpark_deadline;
3752 				if (time_before(deadline, tmp))
3753 					deadline = tmp;
3754 				else if (time_before_eq(tmp, jiffies))
3755 					continue;
3756 				if (ehc->unloaded_mask & (1 << dev->devno))
3757 					continue;
3758 
3759 				ata_eh_park_issue_cmd(dev, 1);
3760 			}
3761 		}
3762 
3763 		now = jiffies;
3764 		if (time_before_eq(deadline, now))
3765 			break;
3766 
3767 		ata_eh_release(ap);
3768 		deadline = wait_for_completion_timeout(&ap->park_req_pending,
3769 						       deadline - now);
3770 		ata_eh_acquire(ap);
3771 	} while (deadline);
3772 	ata_for_each_link(link, ap, EDGE) {
3773 		ata_for_each_dev(dev, link, ALL) {
3774 			if (!(link->eh_context.unloaded_mask &
3775 			      (1 << dev->devno)))
3776 				continue;
3777 
3778 			ata_eh_park_issue_cmd(dev, 0);
3779 			ata_eh_done(link, dev, ATA_EH_PARK);
3780 		}
3781 	}
3782 
3783 	/* the rest */
3784 	nr_fails = 0;
3785 	ata_for_each_link(link, ap, PMP_FIRST) {
3786 		struct ata_eh_context *ehc = &link->eh_context;
3787 
3788 		if (sata_pmp_attached(ap) && ata_is_host_link(link))
3789 			goto config_lpm;
3790 
3791 		/* revalidate existing devices and attach new ones */
3792 		rc = ata_eh_revalidate_and_attach(link, &dev);
3793 		if (rc)
3794 			goto rest_fail;
3795 
3796 		/* if PMP got attached, return, pmp EH will take care of it */
3797 		if (link->device->class == ATA_DEV_PMP) {
3798 			ehc->i.action = 0;
3799 			return 0;
3800 		}
3801 
3802 		/* configure transfer mode if necessary */
3803 		if (ehc->i.flags & ATA_EHI_SETMODE) {
3804 			rc = ata_set_mode(link, &dev);
3805 			if (rc)
3806 				goto rest_fail;
3807 			ehc->i.flags &= ~ATA_EHI_SETMODE;
3808 		}
3809 
3810 		/* If reset has been issued, clear UA to avoid
3811 		 * disrupting the current users of the device.
3812 		 */
3813 		if (ehc->i.flags & ATA_EHI_DID_RESET) {
3814 			ata_for_each_dev(dev, link, ALL) {
3815 				if (dev->class != ATA_DEV_ATAPI)
3816 					continue;
3817 				rc = atapi_eh_clear_ua(dev);
3818 				if (rc)
3819 					goto rest_fail;
3820 			}
3821 		}
3822 
3823 		/* retry flush if necessary */
3824 		ata_for_each_dev(dev, link, ALL) {
3825 			if (dev->class != ATA_DEV_ATA)
3826 				continue;
3827 			rc = ata_eh_maybe_retry_flush(dev);
3828 			if (rc)
3829 				goto rest_fail;
3830 		}
3831 
3832 	config_lpm:
3833 		/* configure link power saving */
3834 		if (link->lpm_policy != ap->target_lpm_policy) {
3835 			rc = ata_eh_set_lpm(link, ap->target_lpm_policy, &dev);
3836 			if (rc)
3837 				goto rest_fail;
3838 		}
3839 
3840 		/* this link is okay now */
3841 		ehc->i.flags = 0;
3842 		continue;
3843 
3844 	rest_fail:
3845 		nr_fails++;
3846 		if (dev)
3847 			ata_eh_handle_dev_fail(dev, rc);
3848 
3849 		if (ap->pflags & ATA_PFLAG_FROZEN) {
3850 			/* PMP reset requires working host port.
3851 			 * Can't retry if it's frozen.
3852 			 */
3853 			if (sata_pmp_attached(ap))
3854 				goto out;
3855 			break;
3856 		}
3857 	}
3858 
3859 	if (nr_fails)
3860 		goto retry;
3861 
3862  out:
3863 	if (rc && r_failed_link)
3864 		*r_failed_link = link;
3865 
3866 	DPRINTK("EXIT, rc=%d\n", rc);
3867 	return rc;
3868 }
3869 
3870 /**
3871  *	ata_eh_finish - finish up EH
3872  *	@ap: host port to finish EH for
3873  *
3874  *	Recovery is complete.  Clean up EH states and retry or finish
3875  *	failed qcs.
3876  *
3877  *	LOCKING:
3878  *	None.
3879  */
3880 void ata_eh_finish(struct ata_port *ap)
3881 {
3882 	int tag;
3883 
3884 	/* retry or finish qcs */
3885 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
3886 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
3887 
3888 		if (!(qc->flags & ATA_QCFLAG_FAILED))
3889 			continue;
3890 
3891 		if (qc->err_mask) {
3892 			/* FIXME: Once EH migration is complete,
3893 			 * generate sense data in this function,
3894 			 * considering both err_mask and tf.
3895 			 */
3896 			if (qc->flags & ATA_QCFLAG_RETRY)
3897 				ata_eh_qc_retry(qc);
3898 			else
3899 				ata_eh_qc_complete(qc);
3900 		} else {
3901 			if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
3902 				ata_eh_qc_complete(qc);
3903 			} else {
3904 				/* feed zero TF to sense generation */
3905 				memset(&qc->result_tf, 0, sizeof(qc->result_tf));
3906 				ata_eh_qc_retry(qc);
3907 			}
3908 		}
3909 	}
3910 
3911 	/* make sure nr_active_links is zero after EH */
3912 	WARN_ON(ap->nr_active_links);
3913 	ap->nr_active_links = 0;
3914 }
3915 
3916 /**
3917  *	ata_do_eh - do standard error handling
3918  *	@ap: host port to handle error for
3919  *
3920  *	@prereset: prereset method (can be NULL)
3921  *	@softreset: softreset method (can be NULL)
3922  *	@hardreset: hardreset method (can be NULL)
3923  *	@postreset: postreset method (can be NULL)
3924  *
3925  *	Perform standard error handling sequence.
3926  *
3927  *	LOCKING:
3928  *	Kernel thread context (may sleep).
3929  */
3930 void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
3931 	       ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3932 	       ata_postreset_fn_t postreset)
3933 {
3934 	struct ata_device *dev;
3935 	int rc;
3936 
3937 	ata_eh_autopsy(ap);
3938 	ata_eh_report(ap);
3939 
3940 	rc = ata_eh_recover(ap, prereset, softreset, hardreset, postreset,
3941 			    NULL);
3942 	if (rc) {
3943 		ata_for_each_dev(dev, &ap->link, ALL)
3944 			ata_dev_disable(dev);
3945 	}
3946 
3947 	ata_eh_finish(ap);
3948 }
3949 
3950 /**
3951  *	ata_std_error_handler - standard error handler
3952  *	@ap: host port to handle error for
3953  *
3954  *	Standard error handler
3955  *
3956  *	LOCKING:
3957  *	Kernel thread context (may sleep).
3958  */
3959 void ata_std_error_handler(struct ata_port *ap)
3960 {
3961 	struct ata_port_operations *ops = ap->ops;
3962 	ata_reset_fn_t hardreset = ops->hardreset;
3963 
3964 	/* ignore built-in hardreset if SCR access is not available */
3965 	if (hardreset == sata_std_hardreset && !sata_scr_valid(&ap->link))
3966 		hardreset = NULL;
3967 
3968 	ata_do_eh(ap, ops->prereset, ops->softreset, hardreset, ops->postreset);
3969 }
3970 
3971 #ifdef CONFIG_PM
3972 /**
3973  *	ata_eh_handle_port_suspend - perform port suspend operation
3974  *	@ap: port to suspend
3975  *
3976  *	Suspend @ap.
3977  *
3978  *	LOCKING:
3979  *	Kernel thread context (may sleep).
3980  */
3981 static void ata_eh_handle_port_suspend(struct ata_port *ap)
3982 {
3983 	unsigned long flags;
3984 	int rc = 0;
3985 
3986 	/* are we suspending? */
3987 	spin_lock_irqsave(ap->lock, flags);
3988 	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
3989 	    ap->pm_mesg.event == PM_EVENT_ON) {
3990 		spin_unlock_irqrestore(ap->lock, flags);
3991 		return;
3992 	}
3993 	spin_unlock_irqrestore(ap->lock, flags);
3994 
3995 	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);
3996 
3997 	/* tell ACPI we're suspending */
3998 	rc = ata_acpi_on_suspend(ap);
3999 	if (rc)
4000 		goto out;
4001 
4002 	/* suspend */
4003 	ata_eh_freeze_port(ap);
4004 
4005 	if (ap->ops->port_suspend)
4006 		rc = ap->ops->port_suspend(ap, ap->pm_mesg);
4007 
4008 	ata_acpi_set_state(ap, PMSG_SUSPEND);
4009  out:
4010 	/* report result */
4011 	spin_lock_irqsave(ap->lock, flags);
4012 
4013 	ap->pflags &= ~ATA_PFLAG_PM_PENDING;
4014 	if (rc == 0)
4015 		ap->pflags |= ATA_PFLAG_SUSPENDED;
4016 	else if (ap->pflags & ATA_PFLAG_FROZEN)
4017 		ata_port_schedule_eh(ap);
4018 
4019 	if (ap->pm_result) {
4020 		*ap->pm_result = rc;
4021 		ap->pm_result = NULL;
4022 	}
4023 
4024 	spin_unlock_irqrestore(ap->lock, flags);
4025 
4026 	return;
4027 }
4028 
4029 /**
4030  *	ata_eh_handle_port_resume - perform port resume operation
4031  *	@ap: port to resume
4032  *
4033  *	Resume @ap.
4034  *
4035  *	LOCKING:
4036  *	Kernel thread context (may sleep).
4037  */
4038 static void ata_eh_handle_port_resume(struct ata_port *ap)
4039 {
4040 	struct ata_link *link;
4041 	struct ata_device *dev;
4042 	unsigned long flags;
4043 	int rc = 0;
4044 
4045 	/* are we resuming? */
4046 	spin_lock_irqsave(ap->lock, flags);
4047 	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
4048 	    ap->pm_mesg.event != PM_EVENT_ON) {
4049 		spin_unlock_irqrestore(ap->lock, flags);
4050 		return;
4051 	}
4052 	spin_unlock_irqrestore(ap->lock, flags);
4053 
4054 	WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));
4055 
4056 	/*
4057 	 * Error timestamps are in jiffies which doesn't run while
4058 	 * suspended and PHY events during resume isn't too uncommon.
4059 	 * When the two are combined, it can lead to unnecessary speed
4060 	 * downs if the machine is suspended and resumed repeatedly.
4061 	 * Clear error history.
4062 	 */
4063 	ata_for_each_link(link, ap, HOST_FIRST)
4064 		ata_for_each_dev(dev, link, ALL)
4065 			ata_ering_clear(&dev->ering);
4066 
4067 	ata_acpi_set_state(ap, PMSG_ON);
4068 
4069 	if (ap->ops->port_resume)
4070 		rc = ap->ops->port_resume(ap);
4071 
4072 	/* tell ACPI that we're resuming */
4073 	ata_acpi_on_resume(ap);
4074 
4075 	/* report result */
4076 	spin_lock_irqsave(ap->lock, flags);
4077 	ap->pflags &= ~(ATA_PFLAG_PM_PENDING | ATA_PFLAG_SUSPENDED);
4078 	if (ap->pm_result) {
4079 		*ap->pm_result = rc;
4080 		ap->pm_result = NULL;
4081 	}
4082 	spin_unlock_irqrestore(ap->lock, flags);
4083 }
4084 #endif /* CONFIG_PM */
4085