1 /* Driver for USB Mass Storage compliant devices
3 * $Id: transport.c,v 1.47 2002/04/22 03:39:43 mdharm Exp $
5 * Current development and maintenance by:
6 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
8 * Developed with the assistance of:
9 * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
10 * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
11 * (c) 2002 Alan Stern <stern@rowland.org>
14 * (c) 1999 Michael Gee (michael@linuxspecific.com)
16 * This driver is based on the 'USB Mass Storage Class' document. This
17 * describes in detail the protocol used to communicate with such
18 * devices. Clearly, the designers had SCSI and ATAPI commands in
19 * mind when they created this document. The commands are all very
20 * similar to commands in the SCSI-II and ATAPI specifications.
22 * It is important to note that in a number of cases this class
23 * exhibits class-specific exemptions from the USB specification.
24 * Notably the usage of NAK, STALL and ACK differs from the norm, in
25 * that they are used to communicate wait, failed and OK on commands.
27 * Also, for certain devices, the interrupt endpoint is used to convey
28 * status of a command.
30 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
31 * information about this driver.
33 * This program is free software; you can redistribute it and/or modify it
34 * under the terms of the GNU General Public License as published by the
35 * Free Software Foundation; either version 2, or (at your option) any
38 * This program is distributed in the hope that it will be useful, but
39 * WITHOUT ANY WARRANTY; without even the implied warranty of
40 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41 * General Public License for more details.
43 * You should have received a copy of the GNU General Public License along
44 * with this program; if not, write to the Free Software Foundation, Inc.,
45 * 675 Mass Ave, Cambridge, MA 02139, USA.
48 #include <linux/config.h>
49 #include <linux/sched.h>
50 #include <linux/errno.h>
51 #include <linux/slab.h>
53 #include <scsi/scsi.h>
54 #include <scsi/scsi_cmnd.h>
55 #include <scsi/scsi_device.h>
58 #include "transport.h"
64 /***********************************************************************
65 * Data transfer routines
66 ***********************************************************************/
69 * This is subtle, so pay attention:
70 * ---------------------------------
71 * We're very concerned about races with a command abort. Hanging this code
72 * is a sure fire way to hang the kernel. (Note that this discussion applies
73 * only to transactions resulting from a scsi queued-command, since only
74 * these transactions are subject to a scsi abort. Other transactions, such
75 * as those occurring during device-specific initialization, must be handled
76 * by a separate code path.)
78 * The abort function (usb_storage_command_abort() in scsiglue.c) first
79 * sets the machine state and the ABORTING bit in us->flags to prevent
80 * new URBs from being submitted. It then calls usb_stor_stop_transport()
81 * below, which atomically tests-and-clears the URB_ACTIVE bit in us->flags
82 * to see if the current_urb needs to be stopped. Likewise, the SG_ACTIVE
83 * bit is tested to see if the current_sg scatter-gather request needs to be
84 * stopped. The timeout callback routine does much the same thing.
86 * When a disconnect occurs, the DISCONNECTING bit in us->flags is set to
87 * prevent new URBs from being submitted, and usb_stor_stop_transport() is
88 * called to stop any ongoing requests.
90 * The submit function first verifies that the submitting is allowed
91 * (neither ABORTING nor DISCONNECTING bits are set) and that the submit
92 * completes without errors, and only then sets the URB_ACTIVE bit. This
93 * prevents the stop_transport() function from trying to cancel the URB
94 * while the submit call is underway. Next, the submit function must test
95 * the flags to see if an abort or disconnect occurred during the submission
96 * or before the URB_ACTIVE bit was set. If so, it's essential to cancel
97 * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit
98 * is still set). Either way, the function must then wait for the URB to
99 * finish. Note that because the URB_ASYNC_UNLINK flag is set, the URB can
100 * still be in progress even after a call to usb_unlink_urb() returns.
102 * The idea is that (1) once the ABORTING or DISCONNECTING bit is set,
103 * either the stop_transport() function or the submitting function
104 * is guaranteed to call usb_unlink_urb() for an active URB,
105 * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being
106 * called more than once or from being called during usb_submit_urb().
109 /* This is the completion handler which will wake us up when an URB
112 static void usb_stor_blocking_completion(struct urb *urb, struct pt_regs *regs)
114 struct completion *urb_done_ptr = (struct completion *)urb->context;
116 complete(urb_done_ptr);
119 /* This is the timeout handler which will cancel an URB when its timeout
122 static void timeout_handler(unsigned long us_)
124 struct us_data *us = (struct us_data *) us_;
126 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) {
127 US_DEBUGP("Timeout -- cancelling URB\n");
128 usb_unlink_urb(us->current_urb);
132 /* This is the common part of the URB message submission code
134 * All URBs from the usb-storage driver involved in handling a queued scsi
135 * command _must_ pass through this function (or something like it) for the
136 * abort mechanisms to work properly.
138 static int usb_stor_msg_common(struct us_data *us, int timeout)
140 struct completion urb_done;
141 struct timer_list to_timer;
144 /* don't submit URBs during abort/disconnect processing */
145 if (us->flags & ABORTING_OR_DISCONNECTING)
148 /* set up data structures for the wakeup system */
149 init_completion(&urb_done);
151 /* fill the common fields in the URB */
152 us->current_urb->context = &urb_done;
153 us->current_urb->actual_length = 0;
154 us->current_urb->error_count = 0;
155 us->current_urb->status = 0;
157 /* we assume that if transfer_buffer isn't us->iobuf then it
158 * hasn't been mapped for DMA. Yes, this is clunky, but it's
159 * easier than always having the caller tell us whether the
160 * transfer buffer has already been mapped. */
161 us->current_urb->transfer_flags =
162 URB_ASYNC_UNLINK | URB_NO_SETUP_DMA_MAP;
163 if (us->current_urb->transfer_buffer == us->iobuf)
164 us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
165 us->current_urb->transfer_dma = us->iobuf_dma;
166 us->current_urb->setup_dma = us->cr_dma;
169 status = usb_submit_urb(us->current_urb, GFP_NOIO);
171 /* something went wrong */
175 /* since the URB has been submitted successfully, it's now okay
177 set_bit(US_FLIDX_URB_ACTIVE, &us->flags);
179 /* did an abort/disconnect occur during the submission? */
180 if (us->flags & ABORTING_OR_DISCONNECTING) {
182 /* cancel the URB, if it hasn't been cancelled already */
183 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) {
184 US_DEBUGP("-- cancelling URB\n");
185 usb_unlink_urb(us->current_urb);
189 /* submit the timeout timer, if a timeout was requested */
191 init_timer(&to_timer);
192 to_timer.expires = jiffies + timeout;
193 to_timer.function = timeout_handler;
194 to_timer.data = (unsigned long) us;
195 add_timer(&to_timer);
198 /* wait for the completion of the URB */
199 wait_for_completion(&urb_done);
200 clear_bit(US_FLIDX_URB_ACTIVE, &us->flags);
202 /* clean up the timeout timer */
204 del_timer_sync(&to_timer);
206 /* return the URB status */
207 return us->current_urb->status;
211 * Transfer one control message, with timeouts, and allowing early
212 * termination. Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
214 int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
215 u8 request, u8 requesttype, u16 value, u16 index,
216 void *data, u16 size, int timeout)
220 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
221 __FUNCTION__, request, requesttype,
224 /* fill in the devrequest structure */
225 us->cr->bRequestType = requesttype;
226 us->cr->bRequest = request;
227 us->cr->wValue = cpu_to_le16(value);
228 us->cr->wIndex = cpu_to_le16(index);
229 us->cr->wLength = cpu_to_le16(size);
231 /* fill and submit the URB */
232 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
233 (unsigned char*) us->cr, data, size,
234 usb_stor_blocking_completion, NULL);
235 status = usb_stor_msg_common(us, timeout);
237 /* return the actual length of the data transferred if no error */
239 status = us->current_urb->actual_length;
243 /* This is a version of usb_clear_halt() that allows early termination and
244 * doesn't read the status from the device -- this is because some devices
245 * crash their internal firmware when the status is requested after a halt.
247 * A definitive list of these 'bad' devices is too difficult to maintain or
248 * make complete enough to be useful. This problem was first observed on the
249 * Hagiwara FlashGate DUAL unit. However, bus traces reveal that neither
250 * MacOS nor Windows checks the status after clearing a halt.
252 * Since many vendors in this space limit their testing to interoperability
253 * with these two OSes, specification violations like this one are common.
255 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
258 int endp = usb_pipeendpoint(pipe);
260 if (usb_pipein (pipe))
263 result = usb_stor_control_msg(us, us->send_ctrl_pipe,
264 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
265 USB_ENDPOINT_HALT, endp,
268 /* reset the endpoint toggle */
270 usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe),
271 usb_pipeout(pipe), 0);
273 US_DEBUGP("%s: result = %d\n", __FUNCTION__, result);
279 * Interpret the results of a URB transfer
281 * This function prints appropriate debugging messages, clears halts on
282 * non-control endpoints, and translates the status to the corresponding
283 * USB_STOR_XFER_xxx return code.
285 static int interpret_urb_result(struct us_data *us, unsigned int pipe,
286 unsigned int length, int result, unsigned int partial)
288 US_DEBUGP("Status code %d; transferred %u/%u\n",
289 result, partial, length);
292 /* no error code; did we send all the data? */
294 if (partial != length) {
295 US_DEBUGP("-- short transfer\n");
296 return USB_STOR_XFER_SHORT;
299 US_DEBUGP("-- transfer complete\n");
300 return USB_STOR_XFER_GOOD;
304 /* for control endpoints, (used by CB[I]) a stall indicates
305 * a failed command */
306 if (usb_pipecontrol(pipe)) {
307 US_DEBUGP("-- stall on control pipe\n");
308 return USB_STOR_XFER_STALLED;
311 /* for other sorts of endpoint, clear the stall */
312 US_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe);
313 if (usb_stor_clear_halt(us, pipe) < 0)
314 return USB_STOR_XFER_ERROR;
315 return USB_STOR_XFER_STALLED;
317 /* timeout or excessively long NAK */
319 US_DEBUGP("-- timeout or NAK\n");
320 return USB_STOR_XFER_ERROR;
322 /* babble - the device tried to send more than we wanted to read */
324 US_DEBUGP("-- babble\n");
325 return USB_STOR_XFER_LONG;
327 /* the transfer was cancelled by abort, disconnect, or timeout */
329 US_DEBUGP("-- transfer cancelled\n");
330 return USB_STOR_XFER_ERROR;
332 /* short scatter-gather read transfer */
334 US_DEBUGP("-- short read transfer\n");
335 return USB_STOR_XFER_SHORT;
337 /* abort or disconnect in progress */
339 US_DEBUGP("-- abort or disconnect in progress\n");
340 return USB_STOR_XFER_ERROR;
342 /* the catch-all error case */
344 US_DEBUGP("-- unknown error\n");
345 return USB_STOR_XFER_ERROR;
350 * Transfer one control message, without timeouts, but allowing early
351 * termination. Return codes are USB_STOR_XFER_xxx.
353 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
354 u8 request, u8 requesttype, u16 value, u16 index,
355 void *data, u16 size)
359 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
360 __FUNCTION__, request, requesttype,
363 /* fill in the devrequest structure */
364 us->cr->bRequestType = requesttype;
365 us->cr->bRequest = request;
366 us->cr->wValue = cpu_to_le16(value);
367 us->cr->wIndex = cpu_to_le16(index);
368 us->cr->wLength = cpu_to_le16(size);
370 /* fill and submit the URB */
371 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
372 (unsigned char*) us->cr, data, size,
373 usb_stor_blocking_completion, NULL);
374 result = usb_stor_msg_common(us, 0);
376 return interpret_urb_result(us, pipe, size, result,
377 us->current_urb->actual_length);
381 * Receive one interrupt buffer, without timeouts, but allowing early
382 * termination. Return codes are USB_STOR_XFER_xxx.
384 * This routine always uses us->recv_intr_pipe as the pipe and
385 * us->ep_bInterval as the interrupt interval.
387 static int usb_stor_intr_transfer(struct us_data *us, void *buf,
391 unsigned int pipe = us->recv_intr_pipe;
394 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length);
396 /* calculate the max packet size */
397 maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe));
401 /* fill and submit the URB */
402 usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
403 maxp, usb_stor_blocking_completion, NULL,
405 result = usb_stor_msg_common(us, 0);
407 return interpret_urb_result(us, pipe, length, result,
408 us->current_urb->actual_length);
412 * Transfer one buffer via bulk pipe, without timeouts, but allowing early
413 * termination. Return codes are USB_STOR_XFER_xxx. If the bulk pipe
414 * stalls during the transfer, the halt is automatically cleared.
416 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
417 void *buf, unsigned int length, unsigned int *act_len)
421 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length);
423 /* fill and submit the URB */
424 usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
425 usb_stor_blocking_completion, NULL);
426 result = usb_stor_msg_common(us, 0);
428 /* store the actual length of the data transferred */
430 *act_len = us->current_urb->actual_length;
431 return interpret_urb_result(us, pipe, length, result,
432 us->current_urb->actual_length);
436 * Transfer a scatter-gather list via bulk transfer
438 * This function does basically the same thing as usb_stor_bulk_transfer_buf()
439 * above, but it uses the usbcore scatter-gather library.
441 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
442 struct scatterlist *sg, int num_sg, unsigned int length,
443 unsigned int *act_len)
447 /* don't submit s-g requests during abort/disconnect processing */
448 if (us->flags & ABORTING_OR_DISCONNECTING)
449 return USB_STOR_XFER_ERROR;
451 /* initialize the scatter-gather request block */
452 US_DEBUGP("%s: xfer %u bytes, %d entries\n", __FUNCTION__,
454 result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
455 sg, num_sg, length, SLAB_NOIO);
457 US_DEBUGP("usb_sg_init returned %d\n", result);
458 return USB_STOR_XFER_ERROR;
461 /* since the block has been initialized successfully, it's now
462 * okay to cancel it */
463 set_bit(US_FLIDX_SG_ACTIVE, &us->flags);
465 /* did an abort/disconnect occur during the submission? */
466 if (us->flags & ABORTING_OR_DISCONNECTING) {
468 /* cancel the request, if it hasn't been cancelled already */
469 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) {
470 US_DEBUGP("-- cancelling sg request\n");
471 usb_sg_cancel(&us->current_sg);
475 /* wait for the completion of the transfer */
476 usb_sg_wait(&us->current_sg);
477 clear_bit(US_FLIDX_SG_ACTIVE, &us->flags);
479 result = us->current_sg.status;
481 *act_len = us->current_sg.bytes;
482 return interpret_urb_result(us, pipe, length, result,
483 us->current_sg.bytes);
487 * Transfer an entire SCSI command's worth of data payload over the bulk
490 * Note that this uses usb_stor_bulk_transfer_buf() and
491 * usb_stor_bulk_transfer_sglist() to achieve its goals --
492 * this function simply determines whether we're going to use
493 * scatter-gather or not, and acts appropriately.
495 int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
496 void *buf, unsigned int length_left, int use_sg, int *residual)
499 unsigned int partial;
501 /* are we scatter-gathering? */
503 /* use the usb core scatter-gather primitives */
504 result = usb_stor_bulk_transfer_sglist(us, pipe,
505 (struct scatterlist *) buf, use_sg,
506 length_left, &partial);
507 length_left -= partial;
509 /* no scatter-gather, just make the request */
510 result = usb_stor_bulk_transfer_buf(us, pipe, buf,
511 length_left, &partial);
512 length_left -= partial;
515 /* store the residual and return the error code */
517 *residual = length_left;
521 /***********************************************************************
523 ***********************************************************************/
525 /* Invoke the transport and basic error-handling/recovery methods
527 * This is used by the protocol layers to actually send the message to
528 * the device and receive the response.
530 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
535 /* send the command to the transport layer */
537 result = us->transport(srb, us);
539 /* if the command gets aborted by the higher layers, we need to
540 * short-circuit all other processing
542 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
543 US_DEBUGP("-- command was aborted\n");
544 srb->result = DID_ABORT << 16;
548 /* if there is a transport error, reset and don't auto-sense */
549 if (result == USB_STOR_TRANSPORT_ERROR) {
550 US_DEBUGP("-- transport indicates error, resetting\n");
551 srb->result = DID_ERROR << 16;
555 /* if the transport provided its own sense data, don't auto-sense */
556 if (result == USB_STOR_TRANSPORT_NO_SENSE) {
557 srb->result = SAM_STAT_CHECK_CONDITION;
561 srb->result = SAM_STAT_GOOD;
563 /* Determine if we need to auto-sense
565 * I normally don't use a flag like this, but it's almost impossible
566 * to understand what's going on here if I don't.
571 * If we're running the CB transport, which is incapable
572 * of determining status on its own, we will auto-sense
573 * unless the operation involved a data-in transfer. Devices
574 * can signal most data-in errors by stalling the bulk-in pipe.
576 if ((us->protocol == US_PR_CB || us->protocol == US_PR_DPCM_USB) &&
577 srb->sc_data_direction != DMA_FROM_DEVICE) {
578 US_DEBUGP("-- CB transport device requiring auto-sense\n");
583 * If we have a failure, we're going to do a REQUEST_SENSE
584 * automatically. Note that we differentiate between a command
585 * "failure" and an "error" in the transport mechanism.
587 if (result == USB_STOR_TRANSPORT_FAILED) {
588 US_DEBUGP("-- transport indicates command failure\n");
593 * A short transfer on a command where we don't expect it
594 * is unusual, but it doesn't mean we need to auto-sense.
596 if ((srb->resid > 0) &&
597 !((srb->cmnd[0] == REQUEST_SENSE) ||
598 (srb->cmnd[0] == INQUIRY) ||
599 (srb->cmnd[0] == MODE_SENSE) ||
600 (srb->cmnd[0] == LOG_SENSE) ||
601 (srb->cmnd[0] == MODE_SENSE_10))) {
602 US_DEBUGP("-- unexpectedly short transfer\n");
605 /* Now, if we need to do the auto-sense, let's do it */
606 if (need_auto_sense) {
608 void* old_request_buffer;
609 unsigned short old_sg;
610 unsigned old_request_bufflen;
611 unsigned char old_sc_data_direction;
612 unsigned char old_cmd_len;
613 unsigned char old_cmnd[MAX_COMMAND_SIZE];
614 unsigned long old_serial_number;
617 US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
619 /* save the old command */
620 memcpy(old_cmnd, srb->cmnd, MAX_COMMAND_SIZE);
621 old_cmd_len = srb->cmd_len;
623 /* set the command and the LUN */
624 memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
625 srb->cmnd[0] = REQUEST_SENSE;
626 srb->cmnd[1] = old_cmnd[1] & 0xE0;
629 /* FIXME: we must do the protocol translation here */
630 if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI)
635 /* set the transfer direction */
636 old_sc_data_direction = srb->sc_data_direction;
637 srb->sc_data_direction = DMA_FROM_DEVICE;
639 /* use the new buffer we have */
640 old_request_buffer = srb->request_buffer;
641 srb->request_buffer = srb->sense_buffer;
643 /* set the buffer length for transfer */
644 old_request_bufflen = srb->request_bufflen;
645 srb->request_bufflen = 18;
647 /* set up for no scatter-gather use */
648 old_sg = srb->use_sg;
651 /* change the serial number -- toggle the high bit*/
652 old_serial_number = srb->serial_number;
653 srb->serial_number ^= 0x80000000;
655 /* issue the auto-sense command */
656 old_resid = srb->resid;
658 temp_result = us->transport(us->srb, us);
660 /* let's clean up right away */
661 srb->resid = old_resid;
662 srb->request_buffer = old_request_buffer;
663 srb->request_bufflen = old_request_bufflen;
664 srb->use_sg = old_sg;
665 srb->serial_number = old_serial_number;
666 srb->sc_data_direction = old_sc_data_direction;
667 srb->cmd_len = old_cmd_len;
668 memcpy(srb->cmnd, old_cmnd, MAX_COMMAND_SIZE);
670 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
671 US_DEBUGP("-- auto-sense aborted\n");
672 srb->result = DID_ABORT << 16;
675 if (temp_result != USB_STOR_TRANSPORT_GOOD) {
676 US_DEBUGP("-- auto-sense failure\n");
678 /* we skip the reset if this happens to be a
679 * multi-target device, since failure of an
680 * auto-sense is perfectly valid
682 srb->result = DID_ERROR << 16;
683 if (!(us->flags & US_FL_SCM_MULT_TARG))
688 US_DEBUGP("-- Result from auto-sense is %d\n", temp_result);
689 US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
690 srb->sense_buffer[0],
691 srb->sense_buffer[2] & 0xf,
692 srb->sense_buffer[12],
693 srb->sense_buffer[13]);
694 #ifdef CONFIG_USB_STORAGE_DEBUG
696 srb->sense_buffer[2] & 0xf,
697 srb->sense_buffer[12],
698 srb->sense_buffer[13]);
701 /* set the result so the higher layers expect this data */
702 srb->result = SAM_STAT_CHECK_CONDITION;
704 /* If things are really okay, then let's show that. Zero
705 * out the sense buffer so the higher layers won't realize
706 * we did an unsolicited auto-sense. */
707 if (result == USB_STOR_TRANSPORT_GOOD &&
708 /* Filemark 0, ignore EOM, ILI 0, no sense */
709 (srb->sense_buffer[2] & 0xaf) == 0 &&
711 srb->sense_buffer[12] == 0 &&
712 srb->sense_buffer[13] == 0) {
713 srb->result = SAM_STAT_GOOD;
714 srb->sense_buffer[0] = 0x0;
718 /* Did we transfer less than the minimum amount required? */
719 if (srb->result == SAM_STAT_GOOD &&
720 srb->request_bufflen - srb->resid < srb->underflow)
721 srb->result = (DID_ERROR << 16) | (SUGGEST_RETRY << 24);
725 /* Error and abort processing: try to resynchronize with the device
726 * by issuing a port reset. If that fails, try a class-specific
730 /* Let the SCSI layer know we are doing a reset, set the
731 * RESETTING bit, and clear the ABORTING bit so that the reset
733 scsi_lock(us_to_host(us));
734 usb_stor_report_bus_reset(us);
735 set_bit(US_FLIDX_RESETTING, &us->flags);
736 clear_bit(US_FLIDX_ABORTING, &us->flags);
737 scsi_unlock(us_to_host(us));
739 result = usb_stor_port_reset(us);
741 scsi_lock(us_to_host(us));
742 usb_stor_report_device_reset(us);
743 scsi_unlock(us_to_host(us));
744 us->transport_reset(us);
746 clear_bit(US_FLIDX_RESETTING, &us->flags);
749 /* Stop the current URB transfer */
750 void usb_stor_stop_transport(struct us_data *us)
752 US_DEBUGP("%s called\n", __FUNCTION__);
754 /* If the state machine is blocked waiting for an URB,
755 * let's wake it up. The test_and_clear_bit() call
756 * guarantees that if a URB has just been submitted,
757 * it won't be cancelled more than once. */
758 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) {
759 US_DEBUGP("-- cancelling URB\n");
760 usb_unlink_urb(us->current_urb);
763 /* If we are waiting for a scatter-gather operation, cancel it. */
764 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) {
765 US_DEBUGP("-- cancelling sg request\n");
766 usb_sg_cancel(&us->current_sg);
771 * Control/Bulk/Interrupt transport
774 int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us)
776 unsigned int transfer_length = srb->request_bufflen;
777 unsigned int pipe = 0;
781 /* let's send the command via the control pipe */
782 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
784 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
785 us->ifnum, srb->cmnd, srb->cmd_len);
787 /* check the return code for the command */
788 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
790 /* if we stalled the command, it means command failed */
791 if (result == USB_STOR_XFER_STALLED) {
792 return USB_STOR_TRANSPORT_FAILED;
795 /* Uh oh... serious problem here */
796 if (result != USB_STOR_XFER_GOOD) {
797 return USB_STOR_TRANSPORT_ERROR;
801 /* transfer the data payload for this command, if one exists*/
802 if (transfer_length) {
803 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
804 us->recv_bulk_pipe : us->send_bulk_pipe;
805 result = usb_stor_bulk_transfer_sg(us, pipe,
806 srb->request_buffer, transfer_length,
807 srb->use_sg, &srb->resid);
808 US_DEBUGP("CBI data stage result is 0x%x\n", result);
810 /* if we stalled the data transfer it means command failed */
811 if (result == USB_STOR_XFER_STALLED)
812 return USB_STOR_TRANSPORT_FAILED;
813 if (result > USB_STOR_XFER_STALLED)
814 return USB_STOR_TRANSPORT_ERROR;
818 result = usb_stor_intr_transfer(us, us->iobuf, 2);
819 US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n",
820 us->iobuf[0], us->iobuf[1]);
821 if (result != USB_STOR_XFER_GOOD)
822 return USB_STOR_TRANSPORT_ERROR;
824 /* UFI gives us ASC and ASCQ, like a request sense
826 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
827 * devices, so we ignore the information for those commands. Note
828 * that this means we could be ignoring a real error on these
829 * commands, but that can't be helped.
831 if (us->subclass == US_SC_UFI) {
832 if (srb->cmnd[0] == REQUEST_SENSE ||
833 srb->cmnd[0] == INQUIRY)
834 return USB_STOR_TRANSPORT_GOOD;
837 return USB_STOR_TRANSPORT_GOOD;
840 /* If not UFI, we interpret the data as a result code
841 * The first byte should always be a 0x0.
843 * Some bogus devices don't follow that rule. They stuff the ASC
844 * into the first byte -- so if it's non-zero, call it a failure.
847 US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n",
853 /* The second byte & 0x0F should be 0x0 for good, otherwise error */
854 switch (us->iobuf[1] & 0x0F) {
856 return USB_STOR_TRANSPORT_GOOD;
860 return USB_STOR_TRANSPORT_ERROR;
862 /* the CBI spec requires that the bulk pipe must be cleared
863 * following any data-in/out command failure (section 2.4.3.1.3)
867 usb_stor_clear_halt(us, pipe);
868 return USB_STOR_TRANSPORT_FAILED;
872 * Control/Bulk transport
874 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
876 unsigned int transfer_length = srb->request_bufflen;
880 /* let's send the command via the control pipe */
881 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
883 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
884 us->ifnum, srb->cmnd, srb->cmd_len);
886 /* check the return code for the command */
887 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
889 /* if we stalled the command, it means command failed */
890 if (result == USB_STOR_XFER_STALLED) {
891 return USB_STOR_TRANSPORT_FAILED;
894 /* Uh oh... serious problem here */
895 if (result != USB_STOR_XFER_GOOD) {
896 return USB_STOR_TRANSPORT_ERROR;
900 /* transfer the data payload for this command, if one exists*/
901 if (transfer_length) {
902 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
903 us->recv_bulk_pipe : us->send_bulk_pipe;
904 result = usb_stor_bulk_transfer_sg(us, pipe,
905 srb->request_buffer, transfer_length,
906 srb->use_sg, &srb->resid);
907 US_DEBUGP("CB data stage result is 0x%x\n", result);
909 /* if we stalled the data transfer it means command failed */
910 if (result == USB_STOR_XFER_STALLED)
911 return USB_STOR_TRANSPORT_FAILED;
912 if (result > USB_STOR_XFER_STALLED)
913 return USB_STOR_TRANSPORT_ERROR;
917 /* NOTE: CB does not have a status stage. Silly, I know. So
918 * we have to catch this at a higher level.
920 return USB_STOR_TRANSPORT_GOOD;
924 * Bulk only transport
927 /* Determine what the maximum LUN supported is */
928 int usb_stor_Bulk_max_lun(struct us_data *us)
932 /* issue the command */
933 result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
935 USB_DIR_IN | USB_TYPE_CLASS |
937 0, us->ifnum, us->iobuf, 1, HZ);
939 US_DEBUGP("GetMaxLUN command result is %d, data is %d\n",
940 result, us->iobuf[0]);
942 /* if we have a successful request, return the result */
947 * Some devices (i.e. Iomega Zip100) need this -- apparently
948 * the bulk pipes get STALLed when the GetMaxLUN request is
949 * processed. This is, in theory, harmless to all other devices
950 * (regardless of if they stall or not).
952 if (result == -EPIPE) {
953 usb_stor_clear_halt(us, us->recv_bulk_pipe);
954 usb_stor_clear_halt(us, us->send_bulk_pipe);
958 * Some devices don't like GetMaxLUN. They may STALL the control
959 * pipe, they may return a zero-length result, they may do nothing at
960 * all and timeout, or they may fail in even more bizarrely creative
961 * ways. In these cases the best approach is to use the default
962 * value: only one LUN.
967 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
969 struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
970 struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
971 unsigned int transfer_length = srb->request_bufflen;
972 unsigned int residue;
976 unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
978 /* Take care of BULK32 devices; set extra byte to 0 */
979 if ( unlikely(us->flags & US_FL_BULK32)) {
984 /* set up the command wrapper */
985 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
986 bcb->DataTransferLength = cpu_to_le32(transfer_length);
987 bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0;
988 bcb->Tag = srb->serial_number;
989 bcb->Lun = srb->device->lun;
990 if (us->flags & US_FL_SCM_MULT_TARG)
991 bcb->Lun |= srb->device->id << 4;
992 bcb->Length = srb->cmd_len;
994 /* copy the command payload */
995 memset(bcb->CDB, 0, sizeof(bcb->CDB));
996 memcpy(bcb->CDB, srb->cmnd, bcb->Length);
998 /* send it to out endpoint */
999 US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
1000 le32_to_cpu(bcb->Signature), bcb->Tag,
1001 le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
1002 (bcb->Lun >> 4), (bcb->Lun & 0x0F),
1004 result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
1006 US_DEBUGP("Bulk command transfer result=%d\n", result);
1007 if (result != USB_STOR_XFER_GOOD)
1008 return USB_STOR_TRANSPORT_ERROR;
1011 /* send/receive data payload, if there is any */
1013 /* Some USB-IDE converter chips need a 100us delay between the
1014 * command phase and the data phase. Some devices need a little
1015 * more than that, probably because of clock rate inaccuracies. */
1016 if (unlikely(us->flags & US_FL_GO_SLOW))
1019 if (transfer_length) {
1020 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
1021 us->recv_bulk_pipe : us->send_bulk_pipe;
1022 result = usb_stor_bulk_transfer_sg(us, pipe,
1023 srb->request_buffer, transfer_length,
1024 srb->use_sg, &srb->resid);
1025 US_DEBUGP("Bulk data transfer result 0x%x\n", result);
1026 if (result == USB_STOR_XFER_ERROR)
1027 return USB_STOR_TRANSPORT_ERROR;
1029 /* If the device tried to send back more data than the
1030 * amount requested, the spec requires us to transfer
1031 * the CSW anyway. Since there's no point retrying the
1032 * the command, we'll return fake sense data indicating
1033 * Illegal Request, Invalid Field in CDB.
1035 if (result == USB_STOR_XFER_LONG)
1039 /* See flow chart on pg 15 of the Bulk Only Transport spec for
1040 * an explanation of how this code works.
1043 /* get CSW for device status */
1044 US_DEBUGP("Attempting to get CSW...\n");
1045 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1046 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1048 /* Some broken devices add unnecessary zero-length packets to the
1049 * end of their data transfers. Such packets show up as 0-length
1050 * CSWs. If we encounter such a thing, try to read the CSW again.
1052 if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
1053 US_DEBUGP("Received 0-length CSW; retrying...\n");
1054 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1055 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1058 /* did the attempt to read the CSW fail? */
1059 if (result == USB_STOR_XFER_STALLED) {
1061 /* get the status again */
1062 US_DEBUGP("Attempting to get CSW (2nd try)...\n");
1063 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1064 bcs, US_BULK_CS_WRAP_LEN, NULL);
1067 /* if we still have a failure at this point, we're in trouble */
1068 US_DEBUGP("Bulk status result = %d\n", result);
1069 if (result != USB_STOR_XFER_GOOD)
1070 return USB_STOR_TRANSPORT_ERROR;
1072 /* check bulk status */
1073 residue = le32_to_cpu(bcs->Residue);
1074 US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
1075 le32_to_cpu(bcs->Signature), bcs->Tag,
1076 residue, bcs->Status);
1077 if (bcs->Tag != srb->serial_number || bcs->Status > US_BULK_STAT_PHASE) {
1078 US_DEBUGP("Bulk logical error\n");
1079 return USB_STOR_TRANSPORT_ERROR;
1082 /* Some broken devices report odd signatures, so we do not check them
1083 * for validity against the spec. We store the first one we see,
1084 * and check subsequent transfers for validity against this signature.
1086 if (!us->bcs_signature) {
1087 us->bcs_signature = bcs->Signature;
1088 if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
1089 US_DEBUGP("Learnt BCS signature 0x%08X\n",
1090 le32_to_cpu(us->bcs_signature));
1091 } else if (bcs->Signature != us->bcs_signature) {
1092 US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n",
1093 le32_to_cpu(bcs->Signature),
1094 le32_to_cpu(us->bcs_signature));
1095 return USB_STOR_TRANSPORT_ERROR;
1098 /* try to compute the actual residue, based on how much data
1099 * was really transferred and what the device tells us */
1101 if (!(us->flags & US_FL_IGNORE_RESIDUE)) {
1102 residue = min(residue, transfer_length);
1103 srb->resid = max(srb->resid, (int) residue);
1107 /* based on the status code, we report good or bad */
1108 switch (bcs->Status) {
1109 case US_BULK_STAT_OK:
1110 /* device babbled -- return fake sense data */
1112 memcpy(srb->sense_buffer,
1113 usb_stor_sense_invalidCDB,
1114 sizeof(usb_stor_sense_invalidCDB));
1115 return USB_STOR_TRANSPORT_NO_SENSE;
1118 /* command good -- note that data could be short */
1119 return USB_STOR_TRANSPORT_GOOD;
1121 case US_BULK_STAT_FAIL:
1122 /* command failed */
1123 return USB_STOR_TRANSPORT_FAILED;
1125 case US_BULK_STAT_PHASE:
1126 /* phase error -- note that a transport reset will be
1127 * invoked by the invoke_transport() function
1129 return USB_STOR_TRANSPORT_ERROR;
1132 /* we should never get here, but if we do, we're in trouble */
1133 return USB_STOR_TRANSPORT_ERROR;
1136 /***********************************************************************
1138 ***********************************************************************/
1140 /* This is the common part of the device reset code.
1142 * It's handy that every transport mechanism uses the control endpoint for
1145 * Basically, we send a reset with a 5-second timeout, so we don't get
1146 * jammed attempting to do the reset.
1148 static int usb_stor_reset_common(struct us_data *us,
1149 u8 request, u8 requesttype,
1150 u16 value, u16 index, void *data, u16 size)
1155 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
1156 US_DEBUGP("No reset during disconnect\n");
1160 result = usb_stor_control_msg(us, us->send_ctrl_pipe,
1161 request, requesttype, value, index, data, size,
1164 US_DEBUGP("Soft reset failed: %d\n", result);
1168 /* Give the device some time to recover from the reset,
1169 * but don't delay disconnect processing. */
1170 wait_event_interruptible_timeout(us->delay_wait,
1171 test_bit(US_FLIDX_DISCONNECTING, &us->flags),
1173 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
1174 US_DEBUGP("Reset interrupted by disconnect\n");
1178 US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n");
1179 result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
1181 US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n");
1182 result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
1184 /* return a result code based on the result of the clear-halts */
1188 US_DEBUGP("Soft reset failed\n");
1190 US_DEBUGP("Soft reset done\n");
1194 /* This issues a CB[I] Reset to the device in question
1196 #define CB_RESET_CMD_SIZE 12
1198 int usb_stor_CB_reset(struct us_data *us)
1200 US_DEBUGP("%s called\n", __FUNCTION__);
1202 memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
1203 us->iobuf[0] = SEND_DIAGNOSTIC;
1205 return usb_stor_reset_common(us, US_CBI_ADSC,
1206 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1207 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
1210 /* This issues a Bulk-only Reset to the device in question, including
1211 * clearing the subsequent endpoint halts that may occur.
1213 int usb_stor_Bulk_reset(struct us_data *us)
1215 US_DEBUGP("%s called\n", __FUNCTION__);
1217 return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
1218 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1219 0, us->ifnum, NULL, 0);
1222 /* Issue a USB port reset to the device. But don't do anything if
1223 * there's more than one interface in the device, so that other users
1224 * are not affected. */
1225 int usb_stor_port_reset(struct us_data *us)
1229 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
1231 US_DEBUGP("No reset during disconnect\n");
1232 } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) {
1234 US_DEBUGP("Refusing to reset a multi-interface device\n");
1237 usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
1239 US_DEBUGP("unable to lock device for reset: %d\n",
1242 result = usb_reset_device(us->pusb_dev);
1244 usb_unlock_device(us->pusb_dev);
1245 US_DEBUGP("usb_reset_device returns %d\n", result);