usb_request.c revision 188983
1/* $FreeBSD: head/sys/dev/usb/usb_request.c 188983 2009-02-24 03:39:13Z thompsa $ */
2/*-
3 * Copyright (c) 1998 The NetBSD Foundation, Inc. All rights reserved.
4 * Copyright (c) 1998 Lennart Augustsson. All rights reserved.
5 * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <dev/usb/usb_defs.h>
30#include <dev/usb/usb_mfunc.h>
31#include <dev/usb/usb_error.h>
32#include <dev/usb/usb.h>
33#include <dev/usb/usb_ioctl.h>
34#include <dev/usb/usbhid.h>
35
36#define	USB_DEBUG_VAR usb2_debug
37
38#include <dev/usb/usb_core.h>
39#include <dev/usb/usb_busdma.h>
40#include <dev/usb/usb_request.h>
41#include <dev/usb/usb_process.h>
42#include <dev/usb/usb_transfer.h>
43#include <dev/usb/usb_debug.h>
44#include <dev/usb/usb_device.h>
45#include <dev/usb/usb_util.h>
46#include <dev/usb/usb_dynamic.h>
47
48#include <dev/usb/usb_controller.h>
49#include <dev/usb/usb_bus.h>
50#include <sys/ctype.h>
51
52#if USB_DEBUG
53static int usb2_pr_poll_delay = USB_PORT_RESET_DELAY;
54static int usb2_pr_recovery_delay = USB_PORT_RESET_RECOVERY;
55static int usb2_ss_delay = 0;
56
57SYSCTL_INT(_hw_usb2, OID_AUTO, pr_poll_delay, CTLFLAG_RW,
58    &usb2_pr_poll_delay, 0, "USB port reset poll delay in ms");
59SYSCTL_INT(_hw_usb2, OID_AUTO, pr_recovery_delay, CTLFLAG_RW,
60    &usb2_pr_recovery_delay, 0, "USB port reset recovery delay in ms");
61SYSCTL_INT(_hw_usb2, OID_AUTO, ss_delay, CTLFLAG_RW,
62    &usb2_ss_delay, 0, "USB status stage delay in ms");
63#endif
64
65/*------------------------------------------------------------------------*
66 *	usb2_do_request_callback
67 *
68 * This function is the USB callback for generic USB Host control
69 * transfers.
70 *------------------------------------------------------------------------*/
71void
72usb2_do_request_callback(struct usb2_xfer *xfer)
73{
74	;				/* workaround for a bug in "indent" */
75
76	DPRINTF("st=%u\n", USB_GET_STATE(xfer));
77
78	switch (USB_GET_STATE(xfer)) {
79	case USB_ST_SETUP:
80		usb2_start_hardware(xfer);
81		break;
82	default:
83		usb2_cv_signal(xfer->xroot->udev->default_cv);
84		break;
85	}
86}
87
88/*------------------------------------------------------------------------*
89 *	usb2_do_clear_stall_callback
90 *
91 * This function is the USB callback for generic clear stall requests.
92 *------------------------------------------------------------------------*/
93void
94usb2_do_clear_stall_callback(struct usb2_xfer *xfer)
95{
96	struct usb2_device_request req;
97	struct usb2_device *udev;
98	struct usb2_pipe *pipe;
99	struct usb2_pipe *pipe_end;
100	struct usb2_pipe *pipe_first;
101	uint8_t to = USB_EP_MAX;
102
103	udev = xfer->xroot->udev;
104
105	USB_BUS_LOCK(udev->bus);
106
107	/* round robin pipe clear stall */
108
109	pipe = udev->pipe_curr;
110	pipe_end = udev->pipes + USB_EP_MAX;
111	pipe_first = udev->pipes;
112	if (pipe == NULL) {
113		pipe = pipe_first;
114	}
115	switch (USB_GET_STATE(xfer)) {
116	case USB_ST_TRANSFERRED:
117		if (pipe->edesc &&
118		    pipe->is_stalled) {
119			pipe->toggle_next = 0;
120			pipe->is_stalled = 0;
121			/* start up the current or next transfer, if any */
122			usb2_command_wrapper(&pipe->pipe_q,
123			    pipe->pipe_q.curr);
124		}
125		pipe++;
126
127	case USB_ST_SETUP:
128tr_setup:
129		if (pipe == pipe_end) {
130			pipe = pipe_first;
131		}
132		if (pipe->edesc &&
133		    pipe->is_stalled) {
134
135			/* setup a clear-stall packet */
136
137			req.bmRequestType = UT_WRITE_ENDPOINT;
138			req.bRequest = UR_CLEAR_FEATURE;
139			USETW(req.wValue, UF_ENDPOINT_HALT);
140			req.wIndex[0] = pipe->edesc->bEndpointAddress;
141			req.wIndex[1] = 0;
142			USETW(req.wLength, 0);
143
144			/* copy in the transfer */
145
146			usb2_copy_in(xfer->frbuffers, 0, &req, sizeof(req));
147
148			/* set length */
149			xfer->frlengths[0] = sizeof(req);
150			xfer->nframes = 1;
151			USB_BUS_UNLOCK(udev->bus);
152
153			usb2_start_hardware(xfer);
154
155			USB_BUS_LOCK(udev->bus);
156			break;
157		}
158		pipe++;
159		if (--to)
160			goto tr_setup;
161		break;
162
163	default:
164		if (xfer->error == USB_ERR_CANCELLED) {
165			break;
166		}
167		goto tr_setup;
168	}
169
170	/* store current pipe */
171	udev->pipe_curr = pipe;
172	USB_BUS_UNLOCK(udev->bus);
173}
174
175/*------------------------------------------------------------------------*
176 *	usb2_do_request_flags and usb2_do_request
177 *
178 * Description of arguments passed to these functions:
179 *
180 * "udev" - this is the "usb2_device" structure pointer on which the
181 * request should be performed. It is possible to call this function
182 * in both Host Side mode and Device Side mode.
183 *
184 * "mtx" - if this argument is non-NULL the mutex pointed to by it
185 * will get dropped and picked up during the execution of this
186 * function, hence this function sometimes needs to sleep. If this
187 * argument is NULL it has no effect.
188 *
189 * "req" - this argument must always be non-NULL and points to an
190 * 8-byte structure holding the USB request to be done. The USB
191 * request structure has a bit telling the direction of the USB
192 * request, if it is a read or a write.
193 *
194 * "data" - if the "wLength" part of the structure pointed to by "req"
195 * is non-zero this argument must point to a valid kernel buffer which
196 * can hold at least "wLength" bytes. If "wLength" is zero "data" can
197 * be NULL.
198 *
199 * "flags" - here is a list of valid flags:
200 *
201 *  o USB_SHORT_XFER_OK: allows the data transfer to be shorter than
202 *  specified
203 *
204 *  o USB_DELAY_STATUS_STAGE: allows the status stage to be performed
205 *  at a later point in time. This is tunable by the "hw.usb.ss_delay"
206 *  sysctl. This flag is mostly useful for debugging.
207 *
208 *  o USB_USER_DATA_PTR: treat the "data" pointer like a userland
209 *  pointer.
210 *
211 * "actlen" - if non-NULL the actual transfer length will be stored in
212 * the 16-bit unsigned integer pointed to by "actlen". This
213 * information is mostly useful when the "USB_SHORT_XFER_OK" flag is
214 * used.
215 *
216 * "timeout" - gives the timeout for the control transfer in
217 * milliseconds. A "timeout" value less than 50 milliseconds is
218 * treated like a 50 millisecond timeout. A "timeout" value greater
219 * than 30 seconds is treated like a 30 second timeout. This USB stack
220 * does not allow control requests without a timeout.
221 *
222 * NOTE: This function is thread safe. All calls to
223 * "usb2_do_request_flags" will be serialised by the use of an
224 * internal "sx_lock".
225 *
226 * Returns:
227 *    0: Success
228 * Else: Failure
229 *------------------------------------------------------------------------*/
230usb2_error_t
231usb2_do_request_flags(struct usb2_device *udev, struct mtx *mtx,
232    struct usb2_device_request *req, void *data, uint32_t flags,
233    uint16_t *actlen, uint32_t timeout)
234{
235	struct usb2_xfer *xfer;
236	const void *desc;
237	int err = 0;
238	uint32_t start_ticks;
239	uint32_t delta_ticks;
240	uint32_t max_ticks;
241	uint16_t length;
242	uint16_t temp;
243
244	if (timeout < 50) {
245		/* timeout is too small */
246		timeout = 50;
247	}
248	if (timeout > 30000) {
249		/* timeout is too big */
250		timeout = 30000;
251	}
252	length = UGETW(req->wLength);
253
254	DPRINTFN(5, "udev=%p bmRequestType=0x%02x bRequest=0x%02x "
255	    "wValue=0x%02x%02x wIndex=0x%02x%02x wLength=0x%02x%02x\n",
256	    udev, req->bmRequestType, req->bRequest,
257	    req->wValue[1], req->wValue[0],
258	    req->wIndex[1], req->wIndex[0],
259	    req->wLength[1], req->wLength[0]);
260
261	/*
262	 * Set "actlen" to a known value in case the caller does not
263	 * check the return value:
264	 */
265	if (actlen) {
266		*actlen = 0;
267	}
268	if (udev->flags.usb2_mode == USB_MODE_DEVICE) {
269		DPRINTF("USB device mode\n");
270		(usb2_temp_get_desc_p) (udev, req, &desc, &temp);
271		if (length > temp) {
272			if (!(flags & USB_SHORT_XFER_OK)) {
273				return (USB_ERR_SHORT_XFER);
274			}
275			length = temp;
276		}
277		if (actlen) {
278			*actlen = length;
279		}
280		if (length > 0) {
281			if (flags & USB_USER_DATA_PTR) {
282				if (copyout(desc, data, length)) {
283					return (USB_ERR_INVAL);
284				}
285			} else {
286				bcopy(desc, data, length);
287			}
288		}
289		return (0);		/* success */
290	}
291	if (mtx) {
292		mtx_unlock(mtx);
293		if (mtx != &Giant) {
294			mtx_assert(mtx, MA_NOTOWNED);
295		}
296	}
297	/*
298	 * Grab the default sx-lock so that serialisation
299	 * is achieved when multiple threads are involved:
300	 */
301
302	sx_xlock(udev->default_sx);
303
304	/*
305	 * Setup a new USB transfer or use the existing one, if any:
306	 */
307	usb2_default_transfer_setup(udev);
308
309	xfer = udev->default_xfer[0];
310	if (xfer == NULL) {
311		/* most likely out of memory */
312		err = USB_ERR_NOMEM;
313		goto done;
314	}
315	USB_XFER_LOCK(xfer);
316
317	if (flags & USB_DELAY_STATUS_STAGE) {
318		xfer->flags.manual_status = 1;
319	} else {
320		xfer->flags.manual_status = 0;
321	}
322
323	xfer->timeout = timeout;
324
325	start_ticks = ticks;
326
327	max_ticks = USB_MS_TO_TICKS(timeout);
328
329	usb2_copy_in(xfer->frbuffers, 0, req, sizeof(*req));
330
331	xfer->frlengths[0] = sizeof(*req);
332	xfer->nframes = 2;
333
334	while (1) {
335		temp = length;
336		if (temp > xfer->max_data_length) {
337			temp = xfer->max_data_length;
338		}
339		xfer->frlengths[1] = temp;
340
341		if (temp > 0) {
342			if (!(req->bmRequestType & UT_READ)) {
343				if (flags & USB_USER_DATA_PTR) {
344					USB_XFER_UNLOCK(xfer);
345					err = usb2_copy_in_user(xfer->frbuffers + 1,
346					    0, data, temp);
347					USB_XFER_LOCK(xfer);
348					if (err) {
349						err = USB_ERR_INVAL;
350						break;
351					}
352				} else {
353					usb2_copy_in(xfer->frbuffers + 1, 0, data, temp);
354				}
355			}
356			xfer->nframes = 2;
357		} else {
358			if (xfer->frlengths[0] == 0) {
359				if (xfer->flags.manual_status) {
360#if USB_DEBUG
361					int temp;
362
363					temp = usb2_ss_delay;
364					if (temp > 5000) {
365						temp = 5000;
366					}
367					if (temp > 0) {
368						usb2_pause_mtx(
369						    xfer->xroot->xfer_mtx,
370						    USB_MS_TO_TICKS(temp));
371					}
372#endif
373					xfer->flags.manual_status = 0;
374				} else {
375					break;
376				}
377			}
378			xfer->nframes = 1;
379		}
380
381		usb2_transfer_start(xfer);
382
383		while (usb2_transfer_pending(xfer)) {
384			usb2_cv_wait(udev->default_cv,
385			    xfer->xroot->xfer_mtx);
386		}
387
388		err = xfer->error;
389
390		if (err) {
391			break;
392		}
393		/* subtract length of SETUP packet, if any */
394
395		if (xfer->aframes > 0) {
396			xfer->actlen -= xfer->frlengths[0];
397		} else {
398			xfer->actlen = 0;
399		}
400
401		/* check for short packet */
402
403		if (temp > xfer->actlen) {
404			temp = xfer->actlen;
405			if (!(flags & USB_SHORT_XFER_OK)) {
406				err = USB_ERR_SHORT_XFER;
407			}
408			length = temp;
409		}
410		if (temp > 0) {
411			if (req->bmRequestType & UT_READ) {
412				if (flags & USB_USER_DATA_PTR) {
413					USB_XFER_UNLOCK(xfer);
414					err = usb2_copy_out_user(xfer->frbuffers + 1,
415					    0, data, temp);
416					USB_XFER_LOCK(xfer);
417					if (err) {
418						err = USB_ERR_INVAL;
419						break;
420					}
421				} else {
422					usb2_copy_out(xfer->frbuffers + 1,
423					    0, data, temp);
424				}
425			}
426		}
427		/*
428		 * Clear "frlengths[0]" so that we don't send the setup
429		 * packet again:
430		 */
431		xfer->frlengths[0] = 0;
432
433		/* update length and data pointer */
434		length -= temp;
435		data = USB_ADD_BYTES(data, temp);
436
437		if (actlen) {
438			(*actlen) += temp;
439		}
440		/* check for timeout */
441
442		delta_ticks = ticks - start_ticks;
443		if (delta_ticks > max_ticks) {
444			if (!err) {
445				err = USB_ERR_TIMEOUT;
446			}
447		}
448		if (err) {
449			break;
450		}
451	}
452
453	if (err) {
454		/*
455		 * Make sure that the control endpoint is no longer
456		 * blocked in case of a non-transfer related error:
457		 */
458		usb2_transfer_stop(xfer);
459	}
460	USB_XFER_UNLOCK(xfer);
461
462done:
463	sx_xunlock(udev->default_sx);
464
465	if (mtx) {
466		mtx_lock(mtx);
467	}
468	return ((usb2_error_t)err);
469}
470
471/*------------------------------------------------------------------------*
472 *	usb2_do_request_proc - factored out code
473 *
474 * This function is factored out code. It does basically the same like
475 * usb2_do_request_flags, except it will check the status of the
476 * passed process argument before doing the USB request. If the
477 * process is draining the USB_ERR_IOERROR code will be returned. It
478 * is assumed that the mutex associated with the process is locked
479 * when calling this function.
480 *------------------------------------------------------------------------*/
481usb2_error_t
482usb2_do_request_proc(struct usb2_device *udev, struct usb2_process *pproc,
483    struct usb2_device_request *req, void *data, uint32_t flags,
484    uint16_t *actlen, uint32_t timeout)
485{
486	usb2_error_t err;
487	uint16_t len;
488
489	/* get request data length */
490	len = UGETW(req->wLength);
491
492	/* check if the device is being detached */
493	if (usb2_proc_is_gone(pproc)) {
494		err = USB_ERR_IOERROR;
495		goto done;
496	}
497
498	/* forward the USB request */
499	err = usb2_do_request_flags(udev, pproc->up_mtx,
500	    req, data, flags, actlen, timeout);
501
502done:
503	/* on failure we zero the data */
504	/* on short packet we zero the unused data */
505	if ((len != 0) && (req->bmRequestType & UE_DIR_IN)) {
506		if (err)
507			memset(data, 0, len);
508		else if (actlen && *actlen != len)
509			memset(((uint8_t *)data) + *actlen, 0, len - *actlen);
510	}
511	return (err);
512}
513
514/*------------------------------------------------------------------------*
515 *	usb2_req_reset_port
516 *
517 * This function will instruct an USB HUB to perform a reset sequence
518 * on the specified port number.
519 *
520 * Returns:
521 *    0: Success. The USB device should now be at address zero.
522 * Else: Failure. No USB device is present and the USB port should be
523 *       disabled.
524 *------------------------------------------------------------------------*/
525usb2_error_t
526usb2_req_reset_port(struct usb2_device *udev, struct mtx *mtx, uint8_t port)
527{
528	struct usb2_port_status ps;
529	usb2_error_t err;
530	uint16_t n;
531
532#if USB_DEBUG
533	uint16_t pr_poll_delay;
534	uint16_t pr_recovery_delay;
535
536#endif
537	err = usb2_req_set_port_feature(udev, mtx, port, UHF_PORT_RESET);
538	if (err) {
539		goto done;
540	}
541#if USB_DEBUG
542	/* range check input parameters */
543	pr_poll_delay = usb2_pr_poll_delay;
544	if (pr_poll_delay < 1) {
545		pr_poll_delay = 1;
546	} else if (pr_poll_delay > 1000) {
547		pr_poll_delay = 1000;
548	}
549	pr_recovery_delay = usb2_pr_recovery_delay;
550	if (pr_recovery_delay > 1000) {
551		pr_recovery_delay = 1000;
552	}
553#endif
554	n = 0;
555	while (1) {
556#if USB_DEBUG
557		/* wait for the device to recover from reset */
558		usb2_pause_mtx(mtx, USB_MS_TO_TICKS(pr_poll_delay));
559		n += pr_poll_delay;
560#else
561		/* wait for the device to recover from reset */
562		usb2_pause_mtx(mtx, USB_MS_TO_TICKS(USB_PORT_RESET_DELAY));
563		n += USB_PORT_RESET_DELAY;
564#endif
565		err = usb2_req_get_port_status(udev, mtx, &ps, port);
566		if (err) {
567			goto done;
568		}
569		/* if the device disappeared, just give up */
570		if (!(UGETW(ps.wPortStatus) & UPS_CURRENT_CONNECT_STATUS)) {
571			goto done;
572		}
573		/* check if reset is complete */
574		if (UGETW(ps.wPortChange) & UPS_C_PORT_RESET) {
575			break;
576		}
577		/* check for timeout */
578		if (n > 1000) {
579			n = 0;
580			break;
581		}
582	}
583
584	/* clear port reset first */
585	err = usb2_req_clear_port_feature(
586	    udev, mtx, port, UHF_C_PORT_RESET);
587	if (err) {
588		goto done;
589	}
590	/* check for timeout */
591	if (n == 0) {
592		err = USB_ERR_TIMEOUT;
593		goto done;
594	}
595#if USB_DEBUG
596	/* wait for the device to recover from reset */
597	usb2_pause_mtx(mtx, USB_MS_TO_TICKS(pr_recovery_delay));
598#else
599	/* wait for the device to recover from reset */
600	usb2_pause_mtx(mtx, USB_MS_TO_TICKS(USB_PORT_RESET_RECOVERY));
601#endif
602
603done:
604	DPRINTFN(2, "port %d reset returning error=%s\n",
605	    port, usb2_errstr(err));
606	return (err);
607}
608
609/*------------------------------------------------------------------------*
610 *	usb2_req_get_desc
611 *
612 * This function can be used to retrieve USB descriptors. It contains
613 * some additional logic like zeroing of missing descriptor bytes and
614 * retrying an USB descriptor in case of failure. The "min_len"
615 * argument specifies the minimum descriptor length. The "max_len"
616 * argument specifies the maximum descriptor length. If the real
617 * descriptor length is less than the minimum length the missing
618 * byte(s) will be zeroed. The length field, first byte, of the USB
619 * descriptor will get overwritten in case it indicates a length that
620 * is too big. Also the type field, second byte, of the USB descriptor
621 * will get forced to the correct type.
622 *
623 * Returns:
624 *    0: Success
625 * Else: Failure
626 *------------------------------------------------------------------------*/
627usb2_error_t
628usb2_req_get_desc(struct usb2_device *udev, struct mtx *mtx, void *desc,
629    uint16_t min_len, uint16_t max_len,
630    uint16_t id, uint8_t type, uint8_t index,
631    uint8_t retries)
632{
633	struct usb2_device_request req;
634	uint8_t *buf;
635	usb2_error_t err;
636
637	DPRINTFN(4, "id=%d, type=%d, index=%d, max_len=%d\n",
638	    id, type, index, max_len);
639
640	req.bmRequestType = UT_READ_DEVICE;
641	req.bRequest = UR_GET_DESCRIPTOR;
642	USETW2(req.wValue, type, index);
643	USETW(req.wIndex, id);
644
645	while (1) {
646
647		if ((min_len < 2) || (max_len < 2)) {
648			err = USB_ERR_INVAL;
649			goto done;
650		}
651		USETW(req.wLength, min_len);
652
653		err = usb2_do_request_flags(udev, mtx, &req,
654		    desc, 0, NULL, 1000);
655
656		if (err) {
657			if (!retries) {
658				goto done;
659			}
660			retries--;
661
662			usb2_pause_mtx(mtx, hz / 5);
663
664			continue;
665		}
666		buf = desc;
667
668		if (min_len == max_len) {
669
670			/* enforce correct type and length */
671
672			if (buf[0] > min_len) {
673				buf[0] = min_len;
674			}
675			buf[1] = type;
676
677			goto done;
678		}
679		/* range check */
680
681		if (max_len > buf[0]) {
682			max_len = buf[0];
683		}
684		/* zero minimum data */
685
686		while (min_len > max_len) {
687			min_len--;
688			buf[min_len] = 0;
689		}
690
691		/* set new minimum length */
692
693		min_len = max_len;
694	}
695done:
696	return (err);
697}
698
699/*------------------------------------------------------------------------*
700 *	usb2_req_get_string_any
701 *
702 * This function will return the string given by "string_index"
703 * using the first language ID. The maximum length "len" includes
704 * the terminating zero. The "len" argument should be twice as
705 * big pluss 2 bytes, compared with the actual maximum string length !
706 *
707 * Returns:
708 *    0: Success
709 * Else: Failure
710 *------------------------------------------------------------------------*/
711usb2_error_t
712usb2_req_get_string_any(struct usb2_device *udev, struct mtx *mtx, char *buf,
713    uint16_t len, uint8_t string_index)
714{
715	char *s;
716	uint8_t *temp;
717	uint16_t i;
718	uint16_t n;
719	uint16_t c;
720	uint8_t swap;
721	usb2_error_t err;
722
723	if (len == 0) {
724		/* should not happen */
725		return (USB_ERR_NORMAL_COMPLETION);
726	}
727	if (string_index == 0) {
728		/* this is the language table */
729		buf[0] = 0;
730		return (USB_ERR_INVAL);
731	}
732	if (udev->flags.no_strings) {
733		buf[0] = 0;
734		return (USB_ERR_STALLED);
735	}
736	err = usb2_req_get_string_desc
737	    (udev, mtx, buf, len, udev->langid, string_index);
738	if (err) {
739		buf[0] = 0;
740		return (err);
741	}
742	temp = (uint8_t *)buf;
743
744	if (temp[0] < 2) {
745		/* string length is too short */
746		buf[0] = 0;
747		return (USB_ERR_INVAL);
748	}
749	/* reserve one byte for terminating zero */
750	len--;
751
752	/* find maximum length */
753	s = buf;
754	n = (temp[0] / 2) - 1;
755	if (n > len) {
756		n = len;
757	}
758	/* skip descriptor header */
759	temp += 2;
760
761	/* reset swap state */
762	swap = 3;
763
764	/* convert and filter */
765	for (i = 0; (i != n); i++) {
766		c = UGETW(temp + (2 * i));
767
768		/* convert from Unicode, handle buggy strings */
769		if (((c & 0xff00) == 0) && (swap & 1)) {
770			/* Little Endian, default */
771			*s = c;
772			swap = 1;
773		} else if (((c & 0x00ff) == 0) && (swap & 2)) {
774			/* Big Endian */
775			*s = c >> 8;
776			swap = 2;
777		} else {
778			/* silently skip bad character */
779			continue;
780		}
781
782		/*
783		 * Filter by default - we don't allow greater and less than
784		 * signs because they might confuse the dmesg printouts!
785		 */
786		if ((*s == '<') || (*s == '>') || (!isprint(*s))) {
787			/* silently skip bad character */
788			continue;
789		}
790		s++;
791	}
792	*s = 0;				/* zero terminate resulting string */
793	return (USB_ERR_NORMAL_COMPLETION);
794}
795
796/*------------------------------------------------------------------------*
797 *	usb2_req_get_string_desc
798 *
799 * If you don't know the language ID, consider using
800 * "usb2_req_get_string_any()".
801 *
802 * Returns:
803 *    0: Success
804 * Else: Failure
805 *------------------------------------------------------------------------*/
806usb2_error_t
807usb2_req_get_string_desc(struct usb2_device *udev, struct mtx *mtx, void *sdesc,
808    uint16_t max_len, uint16_t lang_id,
809    uint8_t string_index)
810{
811	return (usb2_req_get_desc(udev, mtx, sdesc, 2, max_len, lang_id,
812	    UDESC_STRING, string_index, 0));
813}
814
815/*------------------------------------------------------------------------*
816 *	usb2_req_get_config_desc
817 *
818 * Returns:
819 *    0: Success
820 * Else: Failure
821 *------------------------------------------------------------------------*/
822usb2_error_t
823usb2_req_get_config_desc(struct usb2_device *udev, struct mtx *mtx,
824    struct usb2_config_descriptor *d, uint8_t conf_index)
825{
826	usb2_error_t err;
827
828	DPRINTFN(4, "confidx=%d\n", conf_index);
829
830	err = usb2_req_get_desc(udev, mtx, d, sizeof(*d),
831	    sizeof(*d), 0, UDESC_CONFIG, conf_index, 0);
832	if (err) {
833		goto done;
834	}
835	/* Extra sanity checking */
836	if (UGETW(d->wTotalLength) < sizeof(*d)) {
837		err = USB_ERR_INVAL;
838	}
839done:
840	return (err);
841}
842
843/*------------------------------------------------------------------------*
844 *	usb2_req_get_config_desc_full
845 *
846 * This function gets the complete USB configuration descriptor and
847 * ensures that "wTotalLength" is correct.
848 *
849 * Returns:
850 *    0: Success
851 * Else: Failure
852 *------------------------------------------------------------------------*/
853usb2_error_t
854usb2_req_get_config_desc_full(struct usb2_device *udev, struct mtx *mtx,
855    struct usb2_config_descriptor **ppcd, struct malloc_type *mtype,
856    uint8_t index)
857{
858	struct usb2_config_descriptor cd;
859	struct usb2_config_descriptor *cdesc;
860	uint16_t len;
861	usb2_error_t err;
862
863	DPRINTFN(4, "index=%d\n", index);
864
865	*ppcd = NULL;
866
867	err = usb2_req_get_config_desc(udev, mtx, &cd, index);
868	if (err) {
869		return (err);
870	}
871	/* get full descriptor */
872	len = UGETW(cd.wTotalLength);
873	if (len < sizeof(*cdesc)) {
874		/* corrupt descriptor */
875		return (USB_ERR_INVAL);
876	}
877	cdesc = malloc(len, mtype, M_WAITOK);
878	if (cdesc == NULL) {
879		return (USB_ERR_NOMEM);
880	}
881	err = usb2_req_get_desc(udev, mtx, cdesc, len, len, 0,
882	    UDESC_CONFIG, index, 3);
883	if (err) {
884		free(cdesc, mtype);
885		return (err);
886	}
887	/* make sure that the device is not fooling us: */
888	USETW(cdesc->wTotalLength, len);
889
890	*ppcd = cdesc;
891
892	return (0);			/* success */
893}
894
895/*------------------------------------------------------------------------*
896 *	usb2_req_get_device_desc
897 *
898 * Returns:
899 *    0: Success
900 * Else: Failure
901 *------------------------------------------------------------------------*/
902usb2_error_t
903usb2_req_get_device_desc(struct usb2_device *udev, struct mtx *mtx,
904    struct usb2_device_descriptor *d)
905{
906	DPRINTFN(4, "\n");
907	return (usb2_req_get_desc(udev, mtx, d, sizeof(*d),
908	    sizeof(*d), 0, UDESC_DEVICE, 0, 3));
909}
910
911/*------------------------------------------------------------------------*
912 *	usb2_req_get_alt_interface_no
913 *
914 * Returns:
915 *    0: Success
916 * Else: Failure
917 *------------------------------------------------------------------------*/
918usb2_error_t
919usb2_req_get_alt_interface_no(struct usb2_device *udev, struct mtx *mtx,
920    uint8_t *alt_iface_no, uint8_t iface_index)
921{
922	struct usb2_interface *iface = usb2_get_iface(udev, iface_index);
923	struct usb2_device_request req;
924
925	if ((iface == NULL) || (iface->idesc == NULL)) {
926		return (USB_ERR_INVAL);
927	}
928	req.bmRequestType = UT_READ_INTERFACE;
929	req.bRequest = UR_GET_INTERFACE;
930	USETW(req.wValue, 0);
931	req.wIndex[0] = iface->idesc->bInterfaceNumber;
932	req.wIndex[1] = 0;
933	USETW(req.wLength, 1);
934	return (usb2_do_request(udev, mtx, &req, alt_iface_no));
935}
936
937/*------------------------------------------------------------------------*
938 *	usb2_req_set_alt_interface_no
939 *
940 * Returns:
941 *    0: Success
942 * Else: Failure
943 *------------------------------------------------------------------------*/
944usb2_error_t
945usb2_req_set_alt_interface_no(struct usb2_device *udev, struct mtx *mtx,
946    uint8_t iface_index, uint8_t alt_no)
947{
948	struct usb2_interface *iface = usb2_get_iface(udev, iface_index);
949	struct usb2_device_request req;
950
951	if ((iface == NULL) || (iface->idesc == NULL)) {
952		return (USB_ERR_INVAL);
953	}
954	req.bmRequestType = UT_WRITE_INTERFACE;
955	req.bRequest = UR_SET_INTERFACE;
956	req.wValue[0] = alt_no;
957	req.wValue[1] = 0;
958	req.wIndex[0] = iface->idesc->bInterfaceNumber;
959	req.wIndex[1] = 0;
960	USETW(req.wLength, 0);
961	return (usb2_do_request(udev, mtx, &req, 0));
962}
963
964/*------------------------------------------------------------------------*
965 *	usb2_req_get_device_status
966 *
967 * Returns:
968 *    0: Success
969 * Else: Failure
970 *------------------------------------------------------------------------*/
971usb2_error_t
972usb2_req_get_device_status(struct usb2_device *udev, struct mtx *mtx,
973    struct usb2_status *st)
974{
975	struct usb2_device_request req;
976
977	req.bmRequestType = UT_READ_DEVICE;
978	req.bRequest = UR_GET_STATUS;
979	USETW(req.wValue, 0);
980	USETW(req.wIndex, 0);
981	USETW(req.wLength, sizeof(*st));
982	return (usb2_do_request(udev, mtx, &req, st));
983}
984
985/*------------------------------------------------------------------------*
986 *	usb2_req_get_hub_descriptor
987 *
988 * Returns:
989 *    0: Success
990 * Else: Failure
991 *------------------------------------------------------------------------*/
992usb2_error_t
993usb2_req_get_hub_descriptor(struct usb2_device *udev, struct mtx *mtx,
994    struct usb2_hub_descriptor *hd, uint8_t nports)
995{
996	struct usb2_device_request req;
997	uint16_t len = (nports + 7 + (8 * 8)) / 8;
998
999	req.bmRequestType = UT_READ_CLASS_DEVICE;
1000	req.bRequest = UR_GET_DESCRIPTOR;
1001	USETW2(req.wValue, UDESC_HUB, 0);
1002	USETW(req.wIndex, 0);
1003	USETW(req.wLength, len);
1004	return (usb2_do_request(udev, mtx, &req, hd));
1005}
1006
1007/*------------------------------------------------------------------------*
1008 *	usb2_req_get_hub_status
1009 *
1010 * Returns:
1011 *    0: Success
1012 * Else: Failure
1013 *------------------------------------------------------------------------*/
1014usb2_error_t
1015usb2_req_get_hub_status(struct usb2_device *udev, struct mtx *mtx,
1016    struct usb2_hub_status *st)
1017{
1018	struct usb2_device_request req;
1019
1020	req.bmRequestType = UT_READ_CLASS_DEVICE;
1021	req.bRequest = UR_GET_STATUS;
1022	USETW(req.wValue, 0);
1023	USETW(req.wIndex, 0);
1024	USETW(req.wLength, sizeof(struct usb2_hub_status));
1025	return (usb2_do_request(udev, mtx, &req, st));
1026}
1027
1028/*------------------------------------------------------------------------*
1029 *	usb2_req_set_address
1030 *
1031 * This function is used to set the address for an USB device. After
1032 * port reset the USB device will respond at address zero.
1033 *
1034 * Returns:
1035 *    0: Success
1036 * Else: Failure
1037 *------------------------------------------------------------------------*/
1038usb2_error_t
1039usb2_req_set_address(struct usb2_device *udev, struct mtx *mtx, uint16_t addr)
1040{
1041	struct usb2_device_request req;
1042
1043	DPRINTFN(6, "setting device address=%d\n", addr);
1044
1045	req.bmRequestType = UT_WRITE_DEVICE;
1046	req.bRequest = UR_SET_ADDRESS;
1047	USETW(req.wValue, addr);
1048	USETW(req.wIndex, 0);
1049	USETW(req.wLength, 0);
1050
1051	/* Setting the address should not take more than 1 second ! */
1052	return (usb2_do_request_flags(udev, mtx, &req, NULL,
1053	    USB_DELAY_STATUS_STAGE, NULL, 1000));
1054}
1055
1056/*------------------------------------------------------------------------*
1057 *	usb2_req_get_port_status
1058 *
1059 * Returns:
1060 *    0: Success
1061 * Else: Failure
1062 *------------------------------------------------------------------------*/
1063usb2_error_t
1064usb2_req_get_port_status(struct usb2_device *udev, struct mtx *mtx,
1065    struct usb2_port_status *ps, uint8_t port)
1066{
1067	struct usb2_device_request req;
1068
1069	req.bmRequestType = UT_READ_CLASS_OTHER;
1070	req.bRequest = UR_GET_STATUS;
1071	USETW(req.wValue, 0);
1072	req.wIndex[0] = port;
1073	req.wIndex[1] = 0;
1074	USETW(req.wLength, sizeof *ps);
1075	return (usb2_do_request(udev, mtx, &req, ps));
1076}
1077
1078/*------------------------------------------------------------------------*
1079 *	usb2_req_clear_hub_feature
1080 *
1081 * Returns:
1082 *    0: Success
1083 * Else: Failure
1084 *------------------------------------------------------------------------*/
1085usb2_error_t
1086usb2_req_clear_hub_feature(struct usb2_device *udev, struct mtx *mtx,
1087    uint16_t sel)
1088{
1089	struct usb2_device_request req;
1090
1091	req.bmRequestType = UT_WRITE_CLASS_DEVICE;
1092	req.bRequest = UR_CLEAR_FEATURE;
1093	USETW(req.wValue, sel);
1094	USETW(req.wIndex, 0);
1095	USETW(req.wLength, 0);
1096	return (usb2_do_request(udev, mtx, &req, 0));
1097}
1098
1099/*------------------------------------------------------------------------*
1100 *	usb2_req_set_hub_feature
1101 *
1102 * Returns:
1103 *    0: Success
1104 * Else: Failure
1105 *------------------------------------------------------------------------*/
1106usb2_error_t
1107usb2_req_set_hub_feature(struct usb2_device *udev, struct mtx *mtx,
1108    uint16_t sel)
1109{
1110	struct usb2_device_request req;
1111
1112	req.bmRequestType = UT_WRITE_CLASS_DEVICE;
1113	req.bRequest = UR_SET_FEATURE;
1114	USETW(req.wValue, sel);
1115	USETW(req.wIndex, 0);
1116	USETW(req.wLength, 0);
1117	return (usb2_do_request(udev, mtx, &req, 0));
1118}
1119
1120/*------------------------------------------------------------------------*
1121 *	usb2_req_clear_port_feature
1122 *
1123 * Returns:
1124 *    0: Success
1125 * Else: Failure
1126 *------------------------------------------------------------------------*/
1127usb2_error_t
1128usb2_req_clear_port_feature(struct usb2_device *udev, struct mtx *mtx,
1129    uint8_t port, uint16_t sel)
1130{
1131	struct usb2_device_request req;
1132
1133	req.bmRequestType = UT_WRITE_CLASS_OTHER;
1134	req.bRequest = UR_CLEAR_FEATURE;
1135	USETW(req.wValue, sel);
1136	req.wIndex[0] = port;
1137	req.wIndex[1] = 0;
1138	USETW(req.wLength, 0);
1139	return (usb2_do_request(udev, mtx, &req, 0));
1140}
1141
1142/*------------------------------------------------------------------------*
1143 *	usb2_req_set_port_feature
1144 *
1145 * Returns:
1146 *    0: Success
1147 * Else: Failure
1148 *------------------------------------------------------------------------*/
1149usb2_error_t
1150usb2_req_set_port_feature(struct usb2_device *udev, struct mtx *mtx,
1151    uint8_t port, uint16_t sel)
1152{
1153	struct usb2_device_request req;
1154
1155	req.bmRequestType = UT_WRITE_CLASS_OTHER;
1156	req.bRequest = UR_SET_FEATURE;
1157	USETW(req.wValue, sel);
1158	req.wIndex[0] = port;
1159	req.wIndex[1] = 0;
1160	USETW(req.wLength, 0);
1161	return (usb2_do_request(udev, mtx, &req, 0));
1162}
1163
1164/*------------------------------------------------------------------------*
1165 *	usb2_req_set_protocol
1166 *
1167 * Returns:
1168 *    0: Success
1169 * Else: Failure
1170 *------------------------------------------------------------------------*/
1171usb2_error_t
1172usb2_req_set_protocol(struct usb2_device *udev, struct mtx *mtx,
1173    uint8_t iface_index, uint16_t report)
1174{
1175	struct usb2_interface *iface = usb2_get_iface(udev, iface_index);
1176	struct usb2_device_request req;
1177
1178	if ((iface == NULL) || (iface->idesc == NULL)) {
1179		return (USB_ERR_INVAL);
1180	}
1181	DPRINTFN(5, "iface=%p, report=%d, endpt=%d\n",
1182	    iface, report, iface->idesc->bInterfaceNumber);
1183
1184	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
1185	req.bRequest = UR_SET_PROTOCOL;
1186	USETW(req.wValue, report);
1187	req.wIndex[0] = iface->idesc->bInterfaceNumber;
1188	req.wIndex[1] = 0;
1189	USETW(req.wLength, 0);
1190	return (usb2_do_request(udev, mtx, &req, 0));
1191}
1192
1193/*------------------------------------------------------------------------*
1194 *	usb2_req_set_report
1195 *
1196 * Returns:
1197 *    0: Success
1198 * Else: Failure
1199 *------------------------------------------------------------------------*/
1200usb2_error_t
1201usb2_req_set_report(struct usb2_device *udev, struct mtx *mtx, void *data, uint16_t len,
1202    uint8_t iface_index, uint8_t type, uint8_t id)
1203{
1204	struct usb2_interface *iface = usb2_get_iface(udev, iface_index);
1205	struct usb2_device_request req;
1206
1207	if ((iface == NULL) || (iface->idesc == NULL)) {
1208		return (USB_ERR_INVAL);
1209	}
1210	DPRINTFN(5, "len=%d\n", len);
1211
1212	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
1213	req.bRequest = UR_SET_REPORT;
1214	USETW2(req.wValue, type, id);
1215	req.wIndex[0] = iface->idesc->bInterfaceNumber;
1216	req.wIndex[1] = 0;
1217	USETW(req.wLength, len);
1218	return (usb2_do_request(udev, mtx, &req, data));
1219}
1220
1221/*------------------------------------------------------------------------*
1222 *	usb2_req_get_report
1223 *
1224 * Returns:
1225 *    0: Success
1226 * Else: Failure
1227 *------------------------------------------------------------------------*/
1228usb2_error_t
1229usb2_req_get_report(struct usb2_device *udev, struct mtx *mtx, void *data,
1230    uint16_t len, uint8_t iface_index, uint8_t type, uint8_t id)
1231{
1232	struct usb2_interface *iface = usb2_get_iface(udev, iface_index);
1233	struct usb2_device_request req;
1234
1235	if ((iface == NULL) || (iface->idesc == NULL) || (id == 0)) {
1236		return (USB_ERR_INVAL);
1237	}
1238	DPRINTFN(5, "len=%d\n", len);
1239
1240	req.bmRequestType = UT_READ_CLASS_INTERFACE;
1241	req.bRequest = UR_GET_REPORT;
1242	USETW2(req.wValue, type, id);
1243	req.wIndex[0] = iface->idesc->bInterfaceNumber;
1244	req.wIndex[1] = 0;
1245	USETW(req.wLength, len);
1246	return (usb2_do_request(udev, mtx, &req, data));
1247}
1248
1249/*------------------------------------------------------------------------*
1250 *	usb2_req_set_idle
1251 *
1252 * Returns:
1253 *    0: Success
1254 * Else: Failure
1255 *------------------------------------------------------------------------*/
1256usb2_error_t
1257usb2_req_set_idle(struct usb2_device *udev, struct mtx *mtx,
1258    uint8_t iface_index, uint8_t duration, uint8_t id)
1259{
1260	struct usb2_interface *iface = usb2_get_iface(udev, iface_index);
1261	struct usb2_device_request req;
1262
1263	if ((iface == NULL) || (iface->idesc == NULL)) {
1264		return (USB_ERR_INVAL);
1265	}
1266	DPRINTFN(5, "%d %d\n", duration, id);
1267
1268	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
1269	req.bRequest = UR_SET_IDLE;
1270	USETW2(req.wValue, duration, id);
1271	req.wIndex[0] = iface->idesc->bInterfaceNumber;
1272	req.wIndex[1] = 0;
1273	USETW(req.wLength, 0);
1274	return (usb2_do_request(udev, mtx, &req, 0));
1275}
1276
1277/*------------------------------------------------------------------------*
1278 *	usb2_req_get_report_descriptor
1279 *
1280 * Returns:
1281 *    0: Success
1282 * Else: Failure
1283 *------------------------------------------------------------------------*/
1284usb2_error_t
1285usb2_req_get_report_descriptor(struct usb2_device *udev, struct mtx *mtx,
1286    void *d, uint16_t size, uint8_t iface_index)
1287{
1288	struct usb2_interface *iface = usb2_get_iface(udev, iface_index);
1289	struct usb2_device_request req;
1290
1291	if ((iface == NULL) || (iface->idesc == NULL)) {
1292		return (USB_ERR_INVAL);
1293	}
1294	req.bmRequestType = UT_READ_INTERFACE;
1295	req.bRequest = UR_GET_DESCRIPTOR;
1296	USETW2(req.wValue, UDESC_REPORT, 0);	/* report id should be 0 */
1297	req.wIndex[0] = iface->idesc->bInterfaceNumber;
1298	req.wIndex[1] = 0;
1299	USETW(req.wLength, size);
1300	return (usb2_do_request(udev, mtx, &req, d));
1301}
1302
1303/*------------------------------------------------------------------------*
1304 *	usb2_req_set_config
1305 *
1306 * This function is used to select the current configuration number in
1307 * both USB device side mode and USB host side mode. When setting the
1308 * configuration the function of the interfaces can change.
1309 *
1310 * Returns:
1311 *    0: Success
1312 * Else: Failure
1313 *------------------------------------------------------------------------*/
1314usb2_error_t
1315usb2_req_set_config(struct usb2_device *udev, struct mtx *mtx, uint8_t conf)
1316{
1317	struct usb2_device_request req;
1318
1319	DPRINTF("setting config %d\n", conf);
1320
1321	/* do "set configuration" request */
1322
1323	req.bmRequestType = UT_WRITE_DEVICE;
1324	req.bRequest = UR_SET_CONFIG;
1325	req.wValue[0] = conf;
1326	req.wValue[1] = 0;
1327	USETW(req.wIndex, 0);
1328	USETW(req.wLength, 0);
1329	return (usb2_do_request(udev, mtx, &req, 0));
1330}
1331
1332/*------------------------------------------------------------------------*
1333 *	usb2_req_get_config
1334 *
1335 * Returns:
1336 *    0: Success
1337 * Else: Failure
1338 *------------------------------------------------------------------------*/
1339usb2_error_t
1340usb2_req_get_config(struct usb2_device *udev, struct mtx *mtx, uint8_t *pconf)
1341{
1342	struct usb2_device_request req;
1343
1344	req.bmRequestType = UT_READ_DEVICE;
1345	req.bRequest = UR_GET_CONFIG;
1346	USETW(req.wValue, 0);
1347	USETW(req.wIndex, 0);
1348	USETW(req.wLength, 1);
1349	return (usb2_do_request(udev, mtx, &req, pconf));
1350}
1351
1352/*------------------------------------------------------------------------*
1353 *	usb2_req_re_enumerate
1354 *
1355 * NOTE: After this function returns the hardware is in the
1356 * unconfigured state! The application is responsible for setting a
1357 * new configuration.
1358 *
1359 * Returns:
1360 *    0: Success
1361 * Else: Failure
1362 *------------------------------------------------------------------------*/
1363usb2_error_t
1364usb2_req_re_enumerate(struct usb2_device *udev, struct mtx *mtx)
1365{
1366	struct usb2_device *parent_hub;
1367	usb2_error_t err;
1368	uint8_t old_addr;
1369	uint8_t do_retry = 1;
1370
1371	if (udev->flags.usb2_mode != USB_MODE_HOST) {
1372		return (USB_ERR_INVAL);
1373	}
1374	old_addr = udev->address;
1375	parent_hub = udev->parent_hub;
1376	if (parent_hub == NULL) {
1377		return (USB_ERR_INVAL);
1378	}
1379retry:
1380	err = usb2_req_reset_port(parent_hub, mtx, udev->port_no);
1381	if (err) {
1382		DPRINTFN(0, "addr=%d, port reset failed\n", old_addr);
1383		goto done;
1384	}
1385	/*
1386	 * After that the port has been reset our device should be at
1387	 * address zero:
1388	 */
1389	udev->address = USB_START_ADDR;
1390
1391	/* reset "bMaxPacketSize" */
1392	udev->ddesc.bMaxPacketSize = USB_MAX_IPACKET;
1393
1394	/*
1395	 * Restore device address:
1396	 */
1397	err = usb2_req_set_address(udev, mtx, old_addr);
1398	if (err) {
1399		/* XXX ignore any errors! */
1400		DPRINTFN(0, "addr=%d, set address failed! (ignored)\n",
1401		    old_addr);
1402	}
1403	/* restore device address */
1404	udev->address = old_addr;
1405
1406	/* allow device time to set new address */
1407	usb2_pause_mtx(mtx, USB_MS_TO_TICKS(USB_SET_ADDRESS_SETTLE));
1408
1409	/* get the device descriptor */
1410	err = usb2_req_get_desc(udev, mtx, &udev->ddesc,
1411	    USB_MAX_IPACKET, USB_MAX_IPACKET, 0, UDESC_DEVICE, 0, 0);
1412	if (err) {
1413		DPRINTFN(0, "getting device descriptor "
1414		    "at addr %d failed!\n", udev->address);
1415		goto done;
1416	}
1417	/* get the full device descriptor */
1418	err = usb2_req_get_device_desc(udev, mtx, &udev->ddesc);
1419	if (err) {
1420		DPRINTFN(0, "addr=%d, getting device "
1421		    "descriptor failed!\n", old_addr);
1422		goto done;
1423	}
1424done:
1425	if (err && do_retry) {
1426		/* give the USB firmware some time to load */
1427		usb2_pause_mtx(mtx, hz / 2);
1428		/* no more retries after this retry */
1429		do_retry = 0;
1430		/* try again */
1431		goto retry;
1432	}
1433	/* restore address */
1434	udev->address = old_addr;
1435	return (err);
1436}
1437
1438/*------------------------------------------------------------------------*
1439 *	usb2_req_clear_device_feature
1440 *
1441 * Returns:
1442 *    0: Success
1443 * Else: Failure
1444 *------------------------------------------------------------------------*/
1445usb2_error_t
1446usb2_req_clear_device_feature(struct usb2_device *udev, struct mtx *mtx,
1447    uint16_t sel)
1448{
1449	struct usb2_device_request req;
1450
1451	req.bmRequestType = UT_WRITE_DEVICE;
1452	req.bRequest = UR_CLEAR_FEATURE;
1453	USETW(req.wValue, sel);
1454	USETW(req.wIndex, 0);
1455	USETW(req.wLength, 0);
1456	return (usb2_do_request(udev, mtx, &req, 0));
1457}
1458
1459/*------------------------------------------------------------------------*
1460 *	usb2_req_set_device_feature
1461 *
1462 * Returns:
1463 *    0: Success
1464 * Else: Failure
1465 *------------------------------------------------------------------------*/
1466usb2_error_t
1467usb2_req_set_device_feature(struct usb2_device *udev, struct mtx *mtx,
1468    uint16_t sel)
1469{
1470	struct usb2_device_request req;
1471
1472	req.bmRequestType = UT_WRITE_DEVICE;
1473	req.bRequest = UR_SET_FEATURE;
1474	USETW(req.wValue, sel);
1475	USETW(req.wIndex, 0);
1476	USETW(req.wLength, 0);
1477	return (usb2_do_request(udev, mtx, &req, 0));
1478}
1479