xref: /freebsd/sys/dev/usb/controller/xhci_pci.c (revision 4d718f57c58e4f3431b8dee4eda77eb7c54cd1d2)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2010-2022 Hans Petter Selasky
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/stdint.h>
29 #include <sys/stddef.h>
30 #include <sys/param.h>
31 #include <sys/queue.h>
32 #include <sys/types.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/bus.h>
36 #include <sys/module.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/condvar.h>
40 #include <sys/sysctl.h>
41 #include <sys/sx.h>
42 #include <sys/unistd.h>
43 #include <sys/callout.h>
44 #include <sys/malloc.h>
45 #include <sys/priv.h>
46 
47 #include <dev/usb/usb.h>
48 #include <dev/usb/usbdi.h>
49 
50 #include <dev/usb/usb_core.h>
51 #include <dev/usb/usb_busdma.h>
52 #include <dev/usb/usb_process.h>
53 #include <dev/usb/usb_util.h>
54 
55 #include <dev/usb/usb_controller.h>
56 #include <dev/usb/usb_bus.h>
57 #include <dev/usb/usb_pci.h>
58 #include <dev/usb/controller/xhci.h>
59 #include <dev/usb/controller/xhcireg.h>
60 #include "usb_if.h"
61 
62 #define	PCI_XHCI_VENDORID_AMD		0x1022
63 #define	PCI_XHCI_VENDORID_INTEL		0x8086
64 #define	PCI_XHCI_VENDORID_VMWARE	0x15ad
65 #define	PCI_XHCI_VENDORID_ZHAOXIN	0x1d17
66 
67 static device_probe_t xhci_pci_probe;
68 static device_detach_t xhci_pci_detach;
69 static usb_take_controller_t xhci_pci_take_controller;
70 
71 static device_method_t xhci_device_methods[] = {
72 	/* device interface */
73 	DEVMETHOD(device_probe, xhci_pci_probe),
74 	DEVMETHOD(device_attach, xhci_pci_attach),
75 	DEVMETHOD(device_detach, xhci_pci_detach),
76 	DEVMETHOD(device_suspend, bus_generic_suspend),
77 	DEVMETHOD(device_resume, bus_generic_resume),
78 	DEVMETHOD(device_shutdown, bus_generic_shutdown),
79 	DEVMETHOD(usb_take_controller, xhci_pci_take_controller),
80 
81 	DEVMETHOD_END
82 };
83 
84 DEFINE_CLASS_0(xhci, xhci_pci_driver, xhci_device_methods,
85     sizeof(struct xhci_softc));
86 
87 DRIVER_MODULE(xhci, pci, xhci_pci_driver, NULL, NULL);
88 MODULE_DEPEND(xhci, usb, 1, 1, 1);
89 
90 static const char *
xhci_pci_match(device_t self)91 xhci_pci_match(device_t self)
92 {
93 	uint32_t device_id = pci_get_devid(self);
94 
95 	switch (device_id) {
96 	case 0x145c1022:
97 		return ("AMD KERNCZ USB 3.0 controller");
98 	case 0x148c1022:
99 		return ("AMD Starship USB 3.0 controller");
100 	case 0x149c1022:
101 		return ("AMD Matisse USB 3.0 controller");
102 	case 0x15b61022:
103 	case 0x15b71022:
104 		return ("AMD Raphael/Granite Ridge USB 3.1 controller");
105 	case 0x15b81022:
106 		return ("AMD Raphael/Granite Ridge USB 2.0 controller");
107 	case 0x15e01022:
108 	case 0x15e11022:
109 		return ("AMD Raven USB 3.1 controller");
110 	case 0x43ba1022:
111 		return ("AMD X399 USB 3.0 controller");
112 	case 0x43b91022: /* X370 */
113 	case 0x43bb1022: /* B350 */
114 		return ("AMD 300 Series USB 3.1 controller");
115 	case 0x43d51022:
116 		return ("AMD 400 Series USB 3.1 controller");
117 	case 0x43f71022:
118 		return ("AMD 600 Series USB 3.2 controller");
119 	case 0x78121022:
120 	case 0x78141022:
121 	case 0x79141022:
122 		return ("AMD FCH USB 3.0 controller");
123 
124 	case 0x077815ad:
125 	case 0x077915ad:
126 		return ("VMware USB 3.0 controller");
127 
128 	case 0x145f1d94:
129 		return ("Hygon USB 3.0 controller");
130 
131 	case 0x01941033:
132 		return ("NEC uPD720200 USB 3.0 controller");
133 	case 0x00151912:
134 		return ("NEC uPD720202 USB 3.0 controller");
135 
136 	case 0x10001b73:
137 		return ("Fresco Logic FL1000G USB 3.0 controller");
138 	case 0x10091b73:
139 		return ("Fresco Logic FL1009 USB 3.0 controller");
140 	case 0x11001b73:
141 		return ("Fresco Logic FL1100 USB 3.0 controller");
142 
143 	case 0x10421b21:
144 		return ("ASMedia ASM1042 USB 3.0 controller");
145 	case 0x11421b21:
146 		return ("ASMedia ASM1042A USB 3.0 controller");
147 	case 0x13431b21:
148 		return ("ASMedia ASM1143 USB 3.1 controller");
149 	case 0x32421b21:
150 		return ("ASMedia ASM3242 USB 3.2 controller");
151 
152 	case 0x0b278086:
153 		return ("Intel Goshen Ridge Thunderbolt 4 USB controller");
154 	case 0x0f358086:
155 		return ("Intel BayTrail USB 3.0 controller");
156 	case 0x11388086:
157 		return ("Intel Maple Ridge Thunderbolt 4 USB controller");
158 	case 0x15c18086:
159 	case 0x15d48086:
160 	case 0x15db8086:
161 		return ("Intel Alpine Ridge Thunderbolt 3 USB controller");
162 	case 0x15e98086:
163 	case 0x15ec8086:
164 	case 0x15f08086:
165 		return ("Intel Titan Ridge Thunderbolt 3 USB controller");
166 	case 0x19d08086:
167 		return ("Intel Denverton USB 3.0 controller");
168 	case 0x9c318086:
169 	case 0x1e318086:
170 		return ("Intel Panther Point USB 3.0 controller");
171 	case 0x22b58086:
172 		return ("Intel Braswell USB 3.0 controller");
173 	case 0x31a88086:
174 		return ("Intel Gemini Lake USB 3.0 controller");
175 	case 0x34ed8086:
176 		return ("Intel Ice Lake-LP USB 3.1 controller");
177 	case 0x43ed8086:
178 		return ("Intel Tiger Lake-H USB 3.2 controller");
179 	case 0x461e8086:
180 		return ("Intel Alder Lake-P Thunderbolt 4 USB controller");
181 	case 0x51ed8086:
182 		return ("Intel Alder Lake USB 3.2 controller");
183 	case 0x5aa88086:
184 		return ("Intel Apollo Lake USB 3.0 controller");
185 	case 0x7ae08086:
186 		return ("Intel Alder Lake USB 3.2 controller");
187 	case 0x8a138086:
188 		return ("Intel Ice Lake Thunderbolt 3 USB controller");
189 	case 0x8c318086:
190 		return ("Intel Lynx Point USB 3.0 controller");
191 	case 0x8cb18086:
192 		return ("Intel Wildcat Point USB 3.0 controller");
193 	case 0x8d318086:
194 		return ("Intel Wellsburg USB 3.0 controller");
195 	case 0x9a138086:
196 		return ("Intel Tiger Lake-LP Thunderbolt 4 USB controller");
197 	case 0x9a178086:
198 		return ("Intel Tiger Lake-H Thunderbolt 4 USB controller");
199 	case 0x9cb18086:
200 		return ("Broadwell Integrated PCH-LP chipset USB 3.0 controller");
201 	case 0x9d2f8086:
202 		return ("Intel Sunrise Point-LP USB 3.0 controller");
203 	case 0xa0ed8086:
204 		return ("Intel Tiger Lake-LP USB 3.2 controller");
205 	case 0xa12f8086:
206 		return ("Intel Sunrise Point USB 3.0 controller");
207 	case 0xa1af8086:
208 		return ("Intel Lewisburg USB 3.0 controller");
209 	case 0xa2af8086:
210 		return ("Intel Union Point USB 3.0 controller");
211 	case 0xa36d8086:
212 		return ("Intel Cannon Lake USB 3.1 controller");
213 
214 	case 0xa01b177d:
215 		return ("Cavium ThunderX USB 3.0 controller");
216 
217 	case 0x1ada10de:
218 		return ("NVIDIA TU106 USB 3.1 controller");
219 
220 	case 0x92021d17:
221 		return ("Zhaoxin ZX-100 USB 3.0 controller");
222 	case 0x92031d17:
223 		return ("Zhaoxin ZX-200 USB 3.0 controller");
224 	case 0x92041d17:
225 		return ("Zhaoxin ZX-E USB 3.0 controller");
226 
227 	default:
228 		break;
229 	}
230 
231 	if ((pci_get_class(self) == PCIC_SERIALBUS)
232 	    && (pci_get_subclass(self) == PCIS_SERIALBUS_USB)
233 	    && (pci_get_progif(self) == PCIP_SERIALBUS_USB_XHCI)) {
234 		return ("XHCI (generic) USB 3.0 controller");
235 	}
236 	return (NULL);			/* dunno */
237 }
238 
239 static int
xhci_pci_probe(device_t self)240 xhci_pci_probe(device_t self)
241 {
242 	const char *desc = xhci_pci_match(self);
243 
244 	if (desc) {
245 		device_set_desc(self, desc);
246 		return (BUS_PROBE_DEFAULT);
247 	} else {
248 		return (ENXIO);
249 	}
250 }
251 
252 static int xhci_use_msi = 1;
253 TUNABLE_INT("hw.usb.xhci.msi", &xhci_use_msi);
254 static int xhci_use_msix = 1;
255 TUNABLE_INT("hw.usb.xhci.msix", &xhci_use_msix);
256 
257 static void
xhci_interrupt_poll(void * _sc)258 xhci_interrupt_poll(void *_sc)
259 {
260 	struct xhci_softc *sc = _sc;
261 	USB_BUS_UNLOCK(&sc->sc_bus);
262 	xhci_interrupt(sc);
263 	USB_BUS_LOCK(&sc->sc_bus);
264 	usb_callout_reset(&sc->sc_callout, 1, (void *)&xhci_interrupt_poll, sc);
265 }
266 
267 static int
xhci_pci_port_route(device_t self,uint32_t set,uint32_t clear)268 xhci_pci_port_route(device_t self, uint32_t set, uint32_t clear)
269 {
270 	uint32_t temp;
271 	uint32_t usb3_mask;
272 	uint32_t usb2_mask;
273 
274 	temp = pci_read_config(self, PCI_XHCI_INTEL_USB3_PSSEN, 4) |
275 	    pci_read_config(self, PCI_XHCI_INTEL_XUSB2PR, 4);
276 
277 	temp |= set;
278 	temp &= ~clear;
279 
280 	/* Don't set bits which the hardware doesn't support */
281 	usb3_mask = pci_read_config(self, PCI_XHCI_INTEL_USB3PRM, 4);
282 	usb2_mask = pci_read_config(self, PCI_XHCI_INTEL_USB2PRM, 4);
283 
284 	pci_write_config(self, PCI_XHCI_INTEL_USB3_PSSEN, temp & usb3_mask, 4);
285 	pci_write_config(self, PCI_XHCI_INTEL_XUSB2PR, temp & usb2_mask, 4);
286 
287 	device_printf(self, "Port routing mask set to 0x%08x\n", temp);
288 
289 	return (0);
290 }
291 
292 int
xhci_pci_attach(device_t self)293 xhci_pci_attach(device_t self)
294 {
295 	struct xhci_softc *sc = device_get_softc(self);
296 	int count, err, msix_table, rid;
297 	uint8_t usemsi = 1;
298 	uint8_t usedma32 = 0;
299 
300 	rid = PCI_XHCI_CBMEM;
301 	sc->sc_io_res = bus_alloc_resource_any(self, SYS_RES_MEMORY, &rid,
302 	    RF_ACTIVE);
303 	if (!sc->sc_io_res) {
304 		device_printf(self, "Could not map memory\n");
305 		return (ENOMEM);
306 	}
307 	sc->sc_io_tag = rman_get_bustag(sc->sc_io_res);
308 	sc->sc_io_hdl = rman_get_bushandle(sc->sc_io_res);
309 	sc->sc_io_size = rman_get_size(sc->sc_io_res);
310 
311 	switch (pci_get_devid(self)) {
312 	case 0x10091b73:	/* Fresco Logic FL1009 USB3.0 xHCI Controller */
313 	case 0x8241104c:	/* TUSB73x0 USB3.0 xHCI Controller */
314 		sc->sc_no_deconfigure = 1;
315 		break;
316 	case 0x01941033:	/* NEC uPD720200 USB 3.0 controller */
317 	case 0x00141912:	/* NEC uPD720201 USB 3.0 controller */
318 		/* Don't use 64-bit DMA on these controllers. */
319 		usedma32 = 1;
320 		break;
321 	case 0x10001b73:	/* FL1000G */
322 		/* Fresco Logic host doesn't support MSI. */
323 		usemsi = 0;
324 		break;
325 	case 0x0f358086:	/* BayTrail */
326 	case 0x9c318086:	/* Panther Point */
327 	case 0x1e318086:	/* Panther Point */
328 	case 0x8c318086:	/* Lynx Point */
329 	case 0x8cb18086:	/* Wildcat Point */
330 	case 0x9cb18086:	/* Broadwell Mobile Integrated */
331 		/*
332 		 * On Intel chipsets, reroute ports from EHCI to XHCI
333 		 * controller and use a different IMOD value.
334 		 */
335 		sc->sc_port_route = &xhci_pci_port_route;
336 		sc->sc_imod_default = XHCI_IMOD_DEFAULT_LP;
337 		sc->sc_ctlstep = 1;
338 		break;
339 	default:
340 		break;
341 	}
342 
343 	if (xhci_init(sc, self, usedma32)) {
344 		device_printf(self, "Could not initialize softc\n");
345 		bus_release_resource(self, SYS_RES_MEMORY, PCI_XHCI_CBMEM,
346 		    sc->sc_io_res);
347 		return (ENXIO);
348 	}
349 
350 	pci_enable_busmaster(self);
351 
352 	usb_callout_init_mtx(&sc->sc_callout, &sc->sc_bus.bus_mtx, 0);
353 
354 	rid = 0;
355 	if (xhci_use_msix && (msix_table = pci_msix_table_bar(self)) >= 0) {
356 		if (msix_table == PCI_XHCI_CBMEM) {
357 			sc->sc_msix_res = sc->sc_io_res;
358 		} else {
359 			sc->sc_msix_res = bus_alloc_resource_any(self,
360 			    SYS_RES_MEMORY, &msix_table, RF_ACTIVE);
361 			if (sc->sc_msix_res == NULL) {
362 				/* May not be enabled */
363 				device_printf(self,
364 				    "Unable to map MSI-X table\n");
365 			}
366 		}
367 		if (sc->sc_msix_res != NULL) {
368 			count = 1;
369 			if (pci_alloc_msix(self, &count) == 0) {
370 				if (bootverbose)
371 					device_printf(self, "MSI-X enabled\n");
372 				rid = 1;
373 			} else {
374 				if (sc->sc_msix_res != sc->sc_io_res) {
375 					bus_release_resource(self,
376 					    SYS_RES_MEMORY,
377 					    msix_table, sc->sc_msix_res);
378 				}
379 				sc->sc_msix_res = NULL;
380 			}
381 		}
382 	}
383 	if (rid == 0 && xhci_use_msi && usemsi) {
384 		count = 1;
385 		if (pci_alloc_msi(self, &count) == 0) {
386 			if (bootverbose)
387 				device_printf(self, "MSI enabled\n");
388 			rid = 1;
389 		}
390 	}
391 	sc->sc_irq_res = bus_alloc_resource_any(self, SYS_RES_IRQ, &rid,
392 	    RF_ACTIVE | (rid != 0 ? 0 : RF_SHAREABLE));
393 	if (sc->sc_irq_res == NULL) {
394 		pci_release_msi(self);
395 		device_printf(self, "Could not allocate IRQ\n");
396 		/* goto error; FALLTHROUGH - use polling */
397 	}
398 	sc->sc_bus.bdev = device_add_child(self, "usbus", DEVICE_UNIT_ANY);
399 	if (sc->sc_bus.bdev == NULL) {
400 		device_printf(self, "Could not add USB device\n");
401 		goto error;
402 	}
403 	device_set_ivars(sc->sc_bus.bdev, &sc->sc_bus);
404 
405 	switch (pci_get_vendor(self)) {
406 	case PCI_XHCI_VENDORID_AMD:
407 		strlcpy(sc->sc_vendor, "AMD", sizeof(sc->sc_vendor));
408 		break;
409 	case PCI_XHCI_VENDORID_INTEL:
410 		strlcpy(sc->sc_vendor, "Intel", sizeof(sc->sc_vendor));
411 		break;
412 	case PCI_XHCI_VENDORID_VMWARE:
413 		strlcpy(sc->sc_vendor, "VMware", sizeof(sc->sc_vendor));
414 		break;
415 	case PCI_XHCI_VENDORID_ZHAOXIN:
416 		strlcpy(sc->sc_vendor, "Zhaoxin", sizeof(sc->sc_vendor));
417 		break;
418 	default:
419 		if (bootverbose)
420 			device_printf(self, "(New XHCI DeviceId=0x%08x)\n",
421 			    pci_get_devid(self));
422 		snprintf(sc->sc_vendor, sizeof(sc->sc_vendor),
423 		    "(0x%04x)", pci_get_vendor(self));
424 		break;
425 	}
426 
427 	if (sc->sc_irq_res != NULL && xhci_use_polling() == 0) {
428 		err = bus_setup_intr(self, sc->sc_irq_res, INTR_TYPE_BIO | INTR_MPSAFE,
429 		    NULL, (driver_intr_t *)xhci_interrupt, sc, &sc->sc_intr_hdl);
430 		if (err != 0) {
431 			bus_release_resource(self, SYS_RES_IRQ,
432 			    rman_get_rid(sc->sc_irq_res), sc->sc_irq_res);
433 			sc->sc_irq_res = NULL;
434 			pci_release_msi(self);
435 			device_printf(self, "Could not setup IRQ, err=%d\n", err);
436 			sc->sc_intr_hdl = NULL;
437 		}
438 	}
439 	if (sc->sc_irq_res == NULL || sc->sc_intr_hdl == NULL) {
440 		if (xhci_use_polling() != 0) {
441 			device_printf(self, "Interrupt polling at %dHz\n", hz);
442 			USB_BUS_LOCK(&sc->sc_bus);
443 			xhci_interrupt_poll(sc);
444 			USB_BUS_UNLOCK(&sc->sc_bus);
445 		} else
446 			goto error;
447 	}
448 
449 	xhci_pci_take_controller(self);
450 
451 	err = xhci_halt_controller(sc);
452 
453 	if (err == 0)
454 		err = xhci_start_controller(sc);
455 
456 	if (err == 0)
457 		err = device_probe_and_attach(sc->sc_bus.bdev);
458 
459 	if (err) {
460 		device_printf(self, "XHCI halt/start/probe failed err=%d\n", err);
461 		goto error;
462 	}
463 	return (0);
464 
465 error:
466 	xhci_pci_detach(self);
467 	return (ENXIO);
468 }
469 
470 static int
xhci_pci_detach(device_t self)471 xhci_pci_detach(device_t self)
472 {
473 	struct xhci_softc *sc = device_get_softc(self);
474 	int error;
475 
476 	/* during module unload there are lots of children leftover */
477 	error = bus_generic_detach(self);
478 	if (error != 0)
479 		return (error);
480 
481 	usb_callout_drain(&sc->sc_callout);
482 	xhci_halt_controller(sc);
483 	xhci_reset_controller(sc);
484 
485 	pci_disable_busmaster(self);
486 
487 	if (sc->sc_irq_res && sc->sc_intr_hdl) {
488 		bus_teardown_intr(self, sc->sc_irq_res, sc->sc_intr_hdl);
489 		sc->sc_intr_hdl = NULL;
490 	}
491 	if (sc->sc_irq_res) {
492 		bus_release_resource(self, SYS_RES_IRQ,
493 		    rman_get_rid(sc->sc_irq_res), sc->sc_irq_res);
494 		sc->sc_irq_res = NULL;
495 		pci_release_msi(self);
496 	}
497 	if (sc->sc_msix_res != NULL && sc->sc_msix_res != sc->sc_io_res) {
498 		bus_release_resource(self, SYS_RES_MEMORY,
499 		    rman_get_rid(sc->sc_msix_res), sc->sc_msix_res);
500 		sc->sc_msix_res = NULL;
501 	}
502 	if (sc->sc_io_res) {
503 		bus_release_resource(self, SYS_RES_MEMORY, PCI_XHCI_CBMEM,
504 		    sc->sc_io_res);
505 		sc->sc_io_res = NULL;
506 	}
507 
508 	xhci_uninit(sc);
509 
510 	return (0);
511 }
512 
513 static int
xhci_pci_take_controller(device_t self)514 xhci_pci_take_controller(device_t self)
515 {
516 	struct xhci_softc *sc = device_get_softc(self);
517 	uint32_t cparams;
518 	uint32_t eecp;
519 	uint32_t eec;
520 	uint16_t to;
521 	uint8_t bios_sem;
522 
523 	cparams = XREAD4(sc, capa, XHCI_HCSPARAMS0);
524 
525 	eec = -1;
526 
527 	/* Synchronise with the BIOS if it owns the controller. */
528 	for (eecp = XHCI_HCS0_XECP(cparams) << 2; eecp != 0 && XHCI_XECP_NEXT(eec);
529 	    eecp += XHCI_XECP_NEXT(eec) << 2) {
530 		eec = XREAD4(sc, capa, eecp);
531 
532 		if (XHCI_XECP_ID(eec) != XHCI_ID_USB_LEGACY)
533 			continue;
534 		bios_sem = XREAD1(sc, capa, eecp +
535 		    XHCI_XECP_BIOS_SEM);
536 		if (bios_sem == 0)
537 			continue;
538 		device_printf(sc->sc_bus.bdev, "waiting for BIOS "
539 		    "to give up control\n");
540 		XWRITE1(sc, capa, eecp +
541 		    XHCI_XECP_OS_SEM, 1);
542 		to = 500;
543 		while (1) {
544 			bios_sem = XREAD1(sc, capa, eecp +
545 			    XHCI_XECP_BIOS_SEM);
546 			if (bios_sem == 0)
547 				break;
548 
549 			if (--to == 0) {
550 				device_printf(sc->sc_bus.bdev,
551 				    "timed out waiting for BIOS\n");
552 				break;
553 			}
554 			usb_pause_mtx(NULL, hz / 100);	/* wait 10ms */
555 		}
556 	}
557 	return (0);
558 }
559