xref: /linux/drivers/net/phy/phy.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  * drivers/net/phy/phy.c
3  *
4  * Framework for configuring and reading PHY devices
5  * Based on code in sungem_phy.c and gianfar_phy.c
6  *
7  * Author: Andy Fleming
8  *
9  * Copyright (c) 2004 Freescale Semiconductor, Inc.
10  * Copyright (c) 2006  Maciej W. Rozycki
11  *
12  * This program is free software; you can redistribute  it and/or modify it
13  * under  the terms of  the GNU General  Public License as published by the
14  * Free Software Foundation;  either version 2 of the  License, or (at your
15  * option) any later version.
16  *
17  */
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/errno.h>
21 #include <linux/unistd.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/init.h>
25 #include <linux/delay.h>
26 #include <linux/netdevice.h>
27 #include <linux/etherdevice.h>
28 #include <linux/skbuff.h>
29 #include <linux/spinlock.h>
30 #include <linux/mm.h>
31 #include <linux/module.h>
32 #include <linux/mii.h>
33 #include <linux/ethtool.h>
34 #include <linux/phy.h>
35 #include <linux/timer.h>
36 #include <linux/workqueue.h>
37 
38 #include <asm/io.h>
39 #include <asm/irq.h>
40 #include <asm/uaccess.h>
41 
42 /* Convenience function to print out the current phy status
43  */
44 void phy_print_status(struct phy_device *phydev)
45 {
46 	pr_info("PHY: %s - Link is %s", phydev->dev.bus_id,
47 			phydev->link ? "Up" : "Down");
48 	if (phydev->link)
49 		printk(" - %d/%s", phydev->speed,
50 				DUPLEX_FULL == phydev->duplex ?
51 				"Full" : "Half");
52 
53 	printk("\n");
54 }
55 EXPORT_SYMBOL(phy_print_status);
56 
57 
58 /* Convenience functions for reading/writing a given PHY
59  * register. They MUST NOT be called from interrupt context,
60  * because the bus read/write functions may wait for an interrupt
61  * to conclude the operation. */
62 int phy_read(struct phy_device *phydev, u16 regnum)
63 {
64 	int retval;
65 	struct mii_bus *bus = phydev->bus;
66 
67 	spin_lock_bh(&bus->mdio_lock);
68 	retval = bus->read(bus, phydev->addr, regnum);
69 	spin_unlock_bh(&bus->mdio_lock);
70 
71 	return retval;
72 }
73 EXPORT_SYMBOL(phy_read);
74 
75 int phy_write(struct phy_device *phydev, u16 regnum, u16 val)
76 {
77 	int err;
78 	struct mii_bus *bus = phydev->bus;
79 
80 	spin_lock_bh(&bus->mdio_lock);
81 	err = bus->write(bus, phydev->addr, regnum, val);
82 	spin_unlock_bh(&bus->mdio_lock);
83 
84 	return err;
85 }
86 EXPORT_SYMBOL(phy_write);
87 
88 
89 int phy_clear_interrupt(struct phy_device *phydev)
90 {
91 	int err = 0;
92 
93 	if (phydev->drv->ack_interrupt)
94 		err = phydev->drv->ack_interrupt(phydev);
95 
96 	return err;
97 }
98 
99 
100 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
101 {
102 	int err = 0;
103 
104 	phydev->interrupts = interrupts;
105 	if (phydev->drv->config_intr)
106 		err = phydev->drv->config_intr(phydev);
107 
108 	return err;
109 }
110 
111 
112 /* phy_aneg_done
113  *
114  * description: Reads the status register and returns 0 either if
115  *   auto-negotiation is incomplete, or if there was an error.
116  *   Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
117  */
118 static inline int phy_aneg_done(struct phy_device *phydev)
119 {
120 	int retval;
121 
122 	retval = phy_read(phydev, MII_BMSR);
123 
124 	return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
125 }
126 
127 /* A structure for mapping a particular speed and duplex
128  * combination to a particular SUPPORTED and ADVERTISED value */
129 struct phy_setting {
130 	int speed;
131 	int duplex;
132 	u32 setting;
133 };
134 
135 /* A mapping of all SUPPORTED settings to speed/duplex */
136 static const struct phy_setting settings[] = {
137 	{
138 		.speed = 10000,
139 		.duplex = DUPLEX_FULL,
140 		.setting = SUPPORTED_10000baseT_Full,
141 	},
142 	{
143 		.speed = SPEED_1000,
144 		.duplex = DUPLEX_FULL,
145 		.setting = SUPPORTED_1000baseT_Full,
146 	},
147 	{
148 		.speed = SPEED_1000,
149 		.duplex = DUPLEX_HALF,
150 		.setting = SUPPORTED_1000baseT_Half,
151 	},
152 	{
153 		.speed = SPEED_100,
154 		.duplex = DUPLEX_FULL,
155 		.setting = SUPPORTED_100baseT_Full,
156 	},
157 	{
158 		.speed = SPEED_100,
159 		.duplex = DUPLEX_HALF,
160 		.setting = SUPPORTED_100baseT_Half,
161 	},
162 	{
163 		.speed = SPEED_10,
164 		.duplex = DUPLEX_FULL,
165 		.setting = SUPPORTED_10baseT_Full,
166 	},
167 	{
168 		.speed = SPEED_10,
169 		.duplex = DUPLEX_HALF,
170 		.setting = SUPPORTED_10baseT_Half,
171 	},
172 };
173 
174 #define MAX_NUM_SETTINGS (sizeof(settings)/sizeof(struct phy_setting))
175 
176 /* phy_find_setting
177  *
178  * description: Searches the settings array for the setting which
179  *   matches the desired speed and duplex, and returns the index
180  *   of that setting.  Returns the index of the last setting if
181  *   none of the others match.
182  */
183 static inline int phy_find_setting(int speed, int duplex)
184 {
185 	int idx = 0;
186 
187 	while (idx < ARRAY_SIZE(settings) &&
188 			(settings[idx].speed != speed ||
189 			settings[idx].duplex != duplex))
190 		idx++;
191 
192 	return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
193 }
194 
195 /* phy_find_valid
196  * idx: The first index in settings[] to search
197  * features: A mask of the valid settings
198  *
199  * description: Returns the index of the first valid setting less
200  *   than or equal to the one pointed to by idx, as determined by
201  *   the mask in features.  Returns the index of the last setting
202  *   if nothing else matches.
203  */
204 static inline int phy_find_valid(int idx, u32 features)
205 {
206 	while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
207 		idx++;
208 
209 	return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
210 }
211 
212 /* phy_sanitize_settings
213  *
214  * description: Make sure the PHY is set to supported speeds and
215  *   duplexes.  Drop down by one in this order:  1000/FULL,
216  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF
217  */
218 void phy_sanitize_settings(struct phy_device *phydev)
219 {
220 	u32 features = phydev->supported;
221 	int idx;
222 
223 	/* Sanitize settings based on PHY capabilities */
224 	if ((features & SUPPORTED_Autoneg) == 0)
225 		phydev->autoneg = 0;
226 
227 	idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
228 			features);
229 
230 	phydev->speed = settings[idx].speed;
231 	phydev->duplex = settings[idx].duplex;
232 }
233 EXPORT_SYMBOL(phy_sanitize_settings);
234 
235 /* phy_ethtool_sset:
236  * A generic ethtool sset function.  Handles all the details
237  *
238  * A few notes about parameter checking:
239  * - We don't set port or transceiver, so we don't care what they
240  *   were set to.
241  * - phy_start_aneg() will make sure forced settings are sane, and
242  *   choose the next best ones from the ones selected, so we don't
243  *   care if ethtool tries to give us bad values
244  *
245  */
246 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
247 {
248 	if (cmd->phy_address != phydev->addr)
249 		return -EINVAL;
250 
251 	/* We make sure that we don't pass unsupported
252 	 * values in to the PHY */
253 	cmd->advertising &= phydev->supported;
254 
255 	/* Verify the settings we care about. */
256 	if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
257 		return -EINVAL;
258 
259 	if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
260 		return -EINVAL;
261 
262 	if (cmd->autoneg == AUTONEG_DISABLE
263 			&& ((cmd->speed != SPEED_1000
264 					&& cmd->speed != SPEED_100
265 					&& cmd->speed != SPEED_10)
266 				|| (cmd->duplex != DUPLEX_HALF
267 					&& cmd->duplex != DUPLEX_FULL)))
268 		return -EINVAL;
269 
270 	phydev->autoneg = cmd->autoneg;
271 
272 	phydev->speed = cmd->speed;
273 
274 	phydev->advertising = cmd->advertising;
275 
276 	if (AUTONEG_ENABLE == cmd->autoneg)
277 		phydev->advertising |= ADVERTISED_Autoneg;
278 	else
279 		phydev->advertising &= ~ADVERTISED_Autoneg;
280 
281 	phydev->duplex = cmd->duplex;
282 
283 	/* Restart the PHY */
284 	phy_start_aneg(phydev);
285 
286 	return 0;
287 }
288 EXPORT_SYMBOL(phy_ethtool_sset);
289 
290 int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
291 {
292 	cmd->supported = phydev->supported;
293 
294 	cmd->advertising = phydev->advertising;
295 
296 	cmd->speed = phydev->speed;
297 	cmd->duplex = phydev->duplex;
298 	cmd->port = PORT_MII;
299 	cmd->phy_address = phydev->addr;
300 	cmd->transceiver = XCVR_EXTERNAL;
301 	cmd->autoneg = phydev->autoneg;
302 
303 	return 0;
304 }
305 EXPORT_SYMBOL(phy_ethtool_gset);
306 
307 /* Note that this function is currently incompatible with the
308  * PHYCONTROL layer.  It changes registers without regard to
309  * current state.  Use at own risk
310  */
311 int phy_mii_ioctl(struct phy_device *phydev,
312 		struct mii_ioctl_data *mii_data, int cmd)
313 {
314 	u16 val = mii_data->val_in;
315 
316 	switch (cmd) {
317 	case SIOCGMIIPHY:
318 		mii_data->phy_id = phydev->addr;
319 		break;
320 	case SIOCGMIIREG:
321 		mii_data->val_out = phy_read(phydev, mii_data->reg_num);
322 		break;
323 
324 	case SIOCSMIIREG:
325 		if (!capable(CAP_NET_ADMIN))
326 			return -EPERM;
327 
328 		if (mii_data->phy_id == phydev->addr) {
329 			switch(mii_data->reg_num) {
330 			case MII_BMCR:
331 				if (val & (BMCR_RESET|BMCR_ANENABLE))
332 					phydev->autoneg = AUTONEG_DISABLE;
333 				else
334 					phydev->autoneg = AUTONEG_ENABLE;
335 				if ((!phydev->autoneg) && (val & BMCR_FULLDPLX))
336 					phydev->duplex = DUPLEX_FULL;
337 				else
338 					phydev->duplex = DUPLEX_HALF;
339 				break;
340 			case MII_ADVERTISE:
341 				phydev->advertising = val;
342 				break;
343 			default:
344 				/* do nothing */
345 				break;
346 			}
347 		}
348 
349 		phy_write(phydev, mii_data->reg_num, val);
350 
351 		if (mii_data->reg_num == MII_BMCR
352 				&& val & BMCR_RESET
353 				&& phydev->drv->config_init)
354 			phydev->drv->config_init(phydev);
355 		break;
356 	}
357 
358 	return 0;
359 }
360 
361 /* phy_start_aneg
362  *
363  * description: Sanitizes the settings (if we're not
364  *   autonegotiating them), and then calls the driver's
365  *   config_aneg function.  If the PHYCONTROL Layer is operating,
366  *   we change the state to reflect the beginning of
367  *   Auto-negotiation or forcing.
368  */
369 int phy_start_aneg(struct phy_device *phydev)
370 {
371 	int err;
372 
373 	spin_lock(&phydev->lock);
374 
375 	if (AUTONEG_DISABLE == phydev->autoneg)
376 		phy_sanitize_settings(phydev);
377 
378 	err = phydev->drv->config_aneg(phydev);
379 
380 	if (err < 0)
381 		goto out_unlock;
382 
383 	if (phydev->state != PHY_HALTED) {
384 		if (AUTONEG_ENABLE == phydev->autoneg) {
385 			phydev->state = PHY_AN;
386 			phydev->link_timeout = PHY_AN_TIMEOUT;
387 		} else {
388 			phydev->state = PHY_FORCING;
389 			phydev->link_timeout = PHY_FORCE_TIMEOUT;
390 		}
391 	}
392 
393 out_unlock:
394 	spin_unlock(&phydev->lock);
395 	return err;
396 }
397 EXPORT_SYMBOL(phy_start_aneg);
398 
399 
400 static void phy_change(struct work_struct *work);
401 static void phy_timer(unsigned long data);
402 
403 /* phy_start_machine:
404  *
405  * description: The PHY infrastructure can run a state machine
406  *   which tracks whether the PHY is starting up, negotiating,
407  *   etc.  This function starts the timer which tracks the state
408  *   of the PHY.  If you want to be notified when the state
409  *   changes, pass in the callback, otherwise, pass NULL.  If you
410  *   want to maintain your own state machine, do not call this
411  *   function. */
412 void phy_start_machine(struct phy_device *phydev,
413 		void (*handler)(struct net_device *))
414 {
415 	phydev->adjust_state = handler;
416 
417 	init_timer(&phydev->phy_timer);
418 	phydev->phy_timer.function = &phy_timer;
419 	phydev->phy_timer.data = (unsigned long) phydev;
420 	mod_timer(&phydev->phy_timer, jiffies + HZ);
421 }
422 
423 /* phy_stop_machine
424  *
425  * description: Stops the state machine timer, sets the state to UP
426  *   (unless it wasn't up yet). This function must be called BEFORE
427  *   phy_detach.
428  */
429 void phy_stop_machine(struct phy_device *phydev)
430 {
431 	del_timer_sync(&phydev->phy_timer);
432 
433 	spin_lock(&phydev->lock);
434 	if (phydev->state > PHY_UP)
435 		phydev->state = PHY_UP;
436 	spin_unlock(&phydev->lock);
437 
438 	phydev->adjust_state = NULL;
439 }
440 
441 /* phy_force_reduction
442  *
443  * description: Reduces the speed/duplex settings by
444  *   one notch.  The order is so:
445  *   1000/FULL, 1000/HALF, 100/FULL, 100/HALF,
446  *   10/FULL, 10/HALF.  The function bottoms out at 10/HALF.
447  */
448 static void phy_force_reduction(struct phy_device *phydev)
449 {
450 	int idx;
451 
452 	idx = phy_find_setting(phydev->speed, phydev->duplex);
453 
454 	idx++;
455 
456 	idx = phy_find_valid(idx, phydev->supported);
457 
458 	phydev->speed = settings[idx].speed;
459 	phydev->duplex = settings[idx].duplex;
460 
461 	pr_info("Trying %d/%s\n", phydev->speed,
462 			DUPLEX_FULL == phydev->duplex ?
463 			"FULL" : "HALF");
464 }
465 
466 
467 /* phy_error:
468  *
469  * Moves the PHY to the HALTED state in response to a read
470  * or write error, and tells the controller the link is down.
471  * Must not be called from interrupt context, or while the
472  * phydev->lock is held.
473  */
474 void phy_error(struct phy_device *phydev)
475 {
476 	spin_lock(&phydev->lock);
477 	phydev->state = PHY_HALTED;
478 	spin_unlock(&phydev->lock);
479 }
480 
481 /* phy_interrupt
482  *
483  * description: When a PHY interrupt occurs, the handler disables
484  * interrupts, and schedules a work task to clear the interrupt.
485  */
486 static irqreturn_t phy_interrupt(int irq, void *phy_dat)
487 {
488 	struct phy_device *phydev = phy_dat;
489 
490 	if (PHY_HALTED == phydev->state)
491 		return IRQ_NONE;		/* It can't be ours.  */
492 
493 	/* The MDIO bus is not allowed to be written in interrupt
494 	 * context, so we need to disable the irq here.  A work
495 	 * queue will write the PHY to disable and clear the
496 	 * interrupt, and then reenable the irq line. */
497 	disable_irq_nosync(irq);
498 
499 	schedule_work(&phydev->phy_queue);
500 
501 	return IRQ_HANDLED;
502 }
503 
504 /* Enable the interrupts from the PHY side */
505 int phy_enable_interrupts(struct phy_device *phydev)
506 {
507 	int err;
508 
509 	err = phy_clear_interrupt(phydev);
510 
511 	if (err < 0)
512 		return err;
513 
514 	err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
515 
516 	return err;
517 }
518 EXPORT_SYMBOL(phy_enable_interrupts);
519 
520 /* Disable the PHY interrupts from the PHY side */
521 int phy_disable_interrupts(struct phy_device *phydev)
522 {
523 	int err;
524 
525 	/* Disable PHY interrupts */
526 	err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
527 
528 	if (err)
529 		goto phy_err;
530 
531 	/* Clear the interrupt */
532 	err = phy_clear_interrupt(phydev);
533 
534 	if (err)
535 		goto phy_err;
536 
537 	return 0;
538 
539 phy_err:
540 	phy_error(phydev);
541 
542 	return err;
543 }
544 EXPORT_SYMBOL(phy_disable_interrupts);
545 
546 /* phy_start_interrupts
547  *
548  * description: Request the interrupt for the given PHY.  If
549  *   this fails, then we set irq to PHY_POLL.
550  *   Otherwise, we enable the interrupts in the PHY.
551  *   Returns 0 on success.
552  *   This should only be called with a valid IRQ number.
553  */
554 int phy_start_interrupts(struct phy_device *phydev)
555 {
556 	int err = 0;
557 
558 	INIT_WORK(&phydev->phy_queue, phy_change);
559 
560 	if (request_irq(phydev->irq, phy_interrupt,
561 				IRQF_SHARED,
562 				"phy_interrupt",
563 				phydev) < 0) {
564 		printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
565 				phydev->bus->name,
566 				phydev->irq);
567 		phydev->irq = PHY_POLL;
568 		return 0;
569 	}
570 
571 	err = phy_enable_interrupts(phydev);
572 
573 	return err;
574 }
575 EXPORT_SYMBOL(phy_start_interrupts);
576 
577 int phy_stop_interrupts(struct phy_device *phydev)
578 {
579 	int err;
580 
581 	err = phy_disable_interrupts(phydev);
582 
583 	if (err)
584 		phy_error(phydev);
585 
586 	/*
587 	 * Finish any pending work; we might have been scheduled
588 	 * to be called from keventd ourselves, though.
589 	 */
590 	run_scheduled_work(&phydev->phy_queue);
591 
592 	free_irq(phydev->irq, phydev);
593 
594 	return err;
595 }
596 EXPORT_SYMBOL(phy_stop_interrupts);
597 
598 
599 /* Scheduled by the phy_interrupt/timer to handle PHY changes */
600 static void phy_change(struct work_struct *work)
601 {
602 	int err;
603 	struct phy_device *phydev =
604 		container_of(work, struct phy_device, phy_queue);
605 
606 	err = phy_disable_interrupts(phydev);
607 
608 	if (err)
609 		goto phy_err;
610 
611 	spin_lock(&phydev->lock);
612 	if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
613 		phydev->state = PHY_CHANGELINK;
614 	spin_unlock(&phydev->lock);
615 
616 	enable_irq(phydev->irq);
617 
618 	/* Reenable interrupts */
619 	if (PHY_HALTED != phydev->state)
620 		err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
621 
622 	if (err)
623 		goto irq_enable_err;
624 
625 	return;
626 
627 irq_enable_err:
628 	disable_irq(phydev->irq);
629 phy_err:
630 	phy_error(phydev);
631 }
632 
633 /* Bring down the PHY link, and stop checking the status. */
634 void phy_stop(struct phy_device *phydev)
635 {
636 	spin_lock(&phydev->lock);
637 
638 	if (PHY_HALTED == phydev->state)
639 		goto out_unlock;
640 
641 	phydev->state = PHY_HALTED;
642 
643 	if (phydev->irq != PHY_POLL) {
644 		/* Disable PHY Interrupts */
645 		phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
646 
647 		/* Clear any pending interrupts */
648 		phy_clear_interrupt(phydev);
649 	}
650 
651 out_unlock:
652 	spin_unlock(&phydev->lock);
653 
654 	/*
655 	 * Cannot call flush_scheduled_work() here as desired because
656 	 * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
657 	 * will not reenable interrupts.
658 	 */
659 }
660 
661 
662 /* phy_start
663  *
664  * description: Indicates the attached device's readiness to
665  *   handle PHY-related work.  Used during startup to start the
666  *   PHY, and after a call to phy_stop() to resume operation.
667  *   Also used to indicate the MDIO bus has cleared an error
668  *   condition.
669  */
670 void phy_start(struct phy_device *phydev)
671 {
672 	spin_lock(&phydev->lock);
673 
674 	switch (phydev->state) {
675 		case PHY_STARTING:
676 			phydev->state = PHY_PENDING;
677 			break;
678 		case PHY_READY:
679 			phydev->state = PHY_UP;
680 			break;
681 		case PHY_HALTED:
682 			phydev->state = PHY_RESUMING;
683 		default:
684 			break;
685 	}
686 	spin_unlock(&phydev->lock);
687 }
688 EXPORT_SYMBOL(phy_stop);
689 EXPORT_SYMBOL(phy_start);
690 
691 /* PHY timer which handles the state machine */
692 static void phy_timer(unsigned long data)
693 {
694 	struct phy_device *phydev = (struct phy_device *)data;
695 	int needs_aneg = 0;
696 	int err = 0;
697 
698 	spin_lock(&phydev->lock);
699 
700 	if (phydev->adjust_state)
701 		phydev->adjust_state(phydev->attached_dev);
702 
703 	switch(phydev->state) {
704 		case PHY_DOWN:
705 		case PHY_STARTING:
706 		case PHY_READY:
707 		case PHY_PENDING:
708 			break;
709 		case PHY_UP:
710 			needs_aneg = 1;
711 
712 			phydev->link_timeout = PHY_AN_TIMEOUT;
713 
714 			break;
715 		case PHY_AN:
716 			err = phy_read_status(phydev);
717 
718 			if (err < 0)
719 				break;
720 
721 			/* If the link is down, give up on
722 			 * negotiation for now */
723 			if (!phydev->link) {
724 				phydev->state = PHY_NOLINK;
725 				netif_carrier_off(phydev->attached_dev);
726 				phydev->adjust_link(phydev->attached_dev);
727 				break;
728 			}
729 
730 			/* Check if negotiation is done.  Break
731 			 * if there's an error */
732 			err = phy_aneg_done(phydev);
733 			if (err < 0)
734 				break;
735 
736 			/* If AN is done, we're running */
737 			if (err > 0) {
738 				phydev->state = PHY_RUNNING;
739 				netif_carrier_on(phydev->attached_dev);
740 				phydev->adjust_link(phydev->attached_dev);
741 
742 			} else if (0 == phydev->link_timeout--) {
743 				int idx;
744 
745 				needs_aneg = 1;
746 				/* If we have the magic_aneg bit,
747 				 * we try again */
748 				if (phydev->drv->flags & PHY_HAS_MAGICANEG)
749 					break;
750 
751 				/* The timer expired, and we still
752 				 * don't have a setting, so we try
753 				 * forcing it until we find one that
754 				 * works, starting from the fastest speed,
755 				 * and working our way down */
756 				idx = phy_find_valid(0, phydev->supported);
757 
758 				phydev->speed = settings[idx].speed;
759 				phydev->duplex = settings[idx].duplex;
760 
761 				phydev->autoneg = AUTONEG_DISABLE;
762 
763 				pr_info("Trying %d/%s\n", phydev->speed,
764 						DUPLEX_FULL ==
765 						phydev->duplex ?
766 						"FULL" : "HALF");
767 			}
768 			break;
769 		case PHY_NOLINK:
770 			err = phy_read_status(phydev);
771 
772 			if (err)
773 				break;
774 
775 			if (phydev->link) {
776 				phydev->state = PHY_RUNNING;
777 				netif_carrier_on(phydev->attached_dev);
778 				phydev->adjust_link(phydev->attached_dev);
779 			}
780 			break;
781 		case PHY_FORCING:
782 			err = genphy_update_link(phydev);
783 
784 			if (err)
785 				break;
786 
787 			if (phydev->link) {
788 				phydev->state = PHY_RUNNING;
789 				netif_carrier_on(phydev->attached_dev);
790 			} else {
791 				if (0 == phydev->link_timeout--) {
792 					phy_force_reduction(phydev);
793 					needs_aneg = 1;
794 				}
795 			}
796 
797 			phydev->adjust_link(phydev->attached_dev);
798 			break;
799 		case PHY_RUNNING:
800 			/* Only register a CHANGE if we are
801 			 * polling */
802 			if (PHY_POLL == phydev->irq)
803 				phydev->state = PHY_CHANGELINK;
804 			break;
805 		case PHY_CHANGELINK:
806 			err = phy_read_status(phydev);
807 
808 			if (err)
809 				break;
810 
811 			if (phydev->link) {
812 				phydev->state = PHY_RUNNING;
813 				netif_carrier_on(phydev->attached_dev);
814 			} else {
815 				phydev->state = PHY_NOLINK;
816 				netif_carrier_off(phydev->attached_dev);
817 			}
818 
819 			phydev->adjust_link(phydev->attached_dev);
820 
821 			if (PHY_POLL != phydev->irq)
822 				err = phy_config_interrupt(phydev,
823 						PHY_INTERRUPT_ENABLED);
824 			break;
825 		case PHY_HALTED:
826 			if (phydev->link) {
827 				phydev->link = 0;
828 				netif_carrier_off(phydev->attached_dev);
829 				phydev->adjust_link(phydev->attached_dev);
830 			}
831 			break;
832 		case PHY_RESUMING:
833 
834 			err = phy_clear_interrupt(phydev);
835 
836 			if (err)
837 				break;
838 
839 			err = phy_config_interrupt(phydev,
840 					PHY_INTERRUPT_ENABLED);
841 
842 			if (err)
843 				break;
844 
845 			if (AUTONEG_ENABLE == phydev->autoneg) {
846 				err = phy_aneg_done(phydev);
847 				if (err < 0)
848 					break;
849 
850 				/* err > 0 if AN is done.
851 				 * Otherwise, it's 0, and we're
852 				 * still waiting for AN */
853 				if (err > 0) {
854 					phydev->state = PHY_RUNNING;
855 				} else {
856 					phydev->state = PHY_AN;
857 					phydev->link_timeout = PHY_AN_TIMEOUT;
858 				}
859 			} else
860 				phydev->state = PHY_RUNNING;
861 			break;
862 	}
863 
864 	spin_unlock(&phydev->lock);
865 
866 	if (needs_aneg)
867 		err = phy_start_aneg(phydev);
868 
869 	if (err < 0)
870 		phy_error(phydev);
871 
872 	mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ);
873 }
874 
875