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 the URB can still be in progress even after a call to
100 * 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 common part of the URB message submission code
121 * All URBs from the usb-storage driver involved in handling a queued scsi
122 * command _must_ pass through this function (or something like it) for the
123 * abort mechanisms to work properly.
125 static int usb_stor_msg_common(struct us_data *us, int timeout)
127 struct completion urb_done;
131 /* don't submit URBs during abort/disconnect processing */
132 if (us->flags & ABORTING_OR_DISCONNECTING)
135 /* set up data structures for the wakeup system */
136 init_completion(&urb_done);
138 /* fill the common fields in the URB */
139 us->current_urb->context = &urb_done;
140 us->current_urb->actual_length = 0;
141 us->current_urb->error_count = 0;
142 us->current_urb->status = 0;
144 /* we assume that if transfer_buffer isn't us->iobuf then it
145 * hasn't been mapped for DMA. Yes, this is clunky, but it's
146 * easier than always having the caller tell us whether the
147 * transfer buffer has already been mapped. */
148 us->current_urb->transfer_flags = URB_NO_SETUP_DMA_MAP;
149 if (us->current_urb->transfer_buffer == us->iobuf)
150 us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
151 us->current_urb->transfer_dma = us->iobuf_dma;
152 us->current_urb->setup_dma = us->cr_dma;
155 status = usb_submit_urb(us->current_urb, GFP_NOIO);
157 /* something went wrong */
161 /* since the URB has been submitted successfully, it's now okay
163 set_bit(US_FLIDX_URB_ACTIVE, &us->flags);
165 /* did an abort/disconnect occur during the submission? */
166 if (us->flags & ABORTING_OR_DISCONNECTING) {
168 /* cancel the URB, if it hasn't been cancelled already */
169 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) {
170 US_DEBUGP("-- cancelling URB\n");
171 usb_unlink_urb(us->current_urb);
175 /* wait for the completion of the URB */
176 timeleft = wait_for_completion_interruptible_timeout(
177 &urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
179 clear_bit(US_FLIDX_URB_ACTIVE, &us->flags);
182 US_DEBUGP("%s -- cancelling URB\n",
183 timeleft == 0 ? "Timeout" : "Signal");
184 usb_unlink_urb(us->current_urb);
187 /* return the URB status */
188 return us->current_urb->status;
192 * Transfer one control message, with timeouts, and allowing early
193 * termination. Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
195 int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
196 u8 request, u8 requesttype, u16 value, u16 index,
197 void *data, u16 size, int timeout)
201 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
202 __FUNCTION__, request, requesttype,
205 /* fill in the devrequest structure */
206 us->cr->bRequestType = requesttype;
207 us->cr->bRequest = request;
208 us->cr->wValue = cpu_to_le16(value);
209 us->cr->wIndex = cpu_to_le16(index);
210 us->cr->wLength = cpu_to_le16(size);
212 /* fill and submit the URB */
213 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
214 (unsigned char*) us->cr, data, size,
215 usb_stor_blocking_completion, NULL);
216 status = usb_stor_msg_common(us, timeout);
218 /* return the actual length of the data transferred if no error */
220 status = us->current_urb->actual_length;
224 /* This is a version of usb_clear_halt() that allows early termination and
225 * doesn't read the status from the device -- this is because some devices
226 * crash their internal firmware when the status is requested after a halt.
228 * A definitive list of these 'bad' devices is too difficult to maintain or
229 * make complete enough to be useful. This problem was first observed on the
230 * Hagiwara FlashGate DUAL unit. However, bus traces reveal that neither
231 * MacOS nor Windows checks the status after clearing a halt.
233 * Since many vendors in this space limit their testing to interoperability
234 * with these two OSes, specification violations like this one are common.
236 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
239 int endp = usb_pipeendpoint(pipe);
241 if (usb_pipein (pipe))
244 result = usb_stor_control_msg(us, us->send_ctrl_pipe,
245 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
246 USB_ENDPOINT_HALT, endp,
249 /* reset the endpoint toggle */
251 usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe),
252 usb_pipeout(pipe), 0);
254 US_DEBUGP("%s: result = %d\n", __FUNCTION__, result);
260 * Interpret the results of a URB transfer
262 * This function prints appropriate debugging messages, clears halts on
263 * non-control endpoints, and translates the status to the corresponding
264 * USB_STOR_XFER_xxx return code.
266 static int interpret_urb_result(struct us_data *us, unsigned int pipe,
267 unsigned int length, int result, unsigned int partial)
269 US_DEBUGP("Status code %d; transferred %u/%u\n",
270 result, partial, length);
273 /* no error code; did we send all the data? */
275 if (partial != length) {
276 US_DEBUGP("-- short transfer\n");
277 return USB_STOR_XFER_SHORT;
280 US_DEBUGP("-- transfer complete\n");
281 return USB_STOR_XFER_GOOD;
285 /* for control endpoints, (used by CB[I]) a stall indicates
286 * a failed command */
287 if (usb_pipecontrol(pipe)) {
288 US_DEBUGP("-- stall on control pipe\n");
289 return USB_STOR_XFER_STALLED;
292 /* for other sorts of endpoint, clear the stall */
293 US_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe);
294 if (usb_stor_clear_halt(us, pipe) < 0)
295 return USB_STOR_XFER_ERROR;
296 return USB_STOR_XFER_STALLED;
298 /* timeout or excessively long NAK */
300 US_DEBUGP("-- timeout or NAK\n");
301 return USB_STOR_XFER_ERROR;
303 /* babble - the device tried to send more than we wanted to read */
305 US_DEBUGP("-- babble\n");
306 return USB_STOR_XFER_LONG;
308 /* the transfer was cancelled by abort, disconnect, or timeout */
310 US_DEBUGP("-- transfer cancelled\n");
311 return USB_STOR_XFER_ERROR;
313 /* short scatter-gather read transfer */
315 US_DEBUGP("-- short read transfer\n");
316 return USB_STOR_XFER_SHORT;
318 /* abort or disconnect in progress */
320 US_DEBUGP("-- abort or disconnect in progress\n");
321 return USB_STOR_XFER_ERROR;
323 /* the catch-all error case */
325 US_DEBUGP("-- unknown error\n");
326 return USB_STOR_XFER_ERROR;
331 * Transfer one control message, without timeouts, but allowing early
332 * termination. Return codes are USB_STOR_XFER_xxx.
334 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
335 u8 request, u8 requesttype, u16 value, u16 index,
336 void *data, u16 size)
340 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
341 __FUNCTION__, request, requesttype,
344 /* fill in the devrequest structure */
345 us->cr->bRequestType = requesttype;
346 us->cr->bRequest = request;
347 us->cr->wValue = cpu_to_le16(value);
348 us->cr->wIndex = cpu_to_le16(index);
349 us->cr->wLength = cpu_to_le16(size);
351 /* fill and submit the URB */
352 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
353 (unsigned char*) us->cr, data, size,
354 usb_stor_blocking_completion, NULL);
355 result = usb_stor_msg_common(us, 0);
357 return interpret_urb_result(us, pipe, size, result,
358 us->current_urb->actual_length);
362 * Receive one interrupt buffer, without timeouts, but allowing early
363 * termination. Return codes are USB_STOR_XFER_xxx.
365 * This routine always uses us->recv_intr_pipe as the pipe and
366 * us->ep_bInterval as the interrupt interval.
368 static int usb_stor_intr_transfer(struct us_data *us, void *buf,
372 unsigned int pipe = us->recv_intr_pipe;
375 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length);
377 /* calculate the max packet size */
378 maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe));
382 /* fill and submit the URB */
383 usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
384 maxp, usb_stor_blocking_completion, NULL,
386 result = usb_stor_msg_common(us, 0);
388 return interpret_urb_result(us, pipe, length, result,
389 us->current_urb->actual_length);
393 * Transfer one buffer via bulk pipe, without timeouts, but allowing early
394 * termination. Return codes are USB_STOR_XFER_xxx. If the bulk pipe
395 * stalls during the transfer, the halt is automatically cleared.
397 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
398 void *buf, unsigned int length, unsigned int *act_len)
402 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length);
404 /* fill and submit the URB */
405 usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
406 usb_stor_blocking_completion, NULL);
407 result = usb_stor_msg_common(us, 0);
409 /* store the actual length of the data transferred */
411 *act_len = us->current_urb->actual_length;
412 return interpret_urb_result(us, pipe, length, result,
413 us->current_urb->actual_length);
417 * Transfer a scatter-gather list via bulk transfer
419 * This function does basically the same thing as usb_stor_bulk_transfer_buf()
420 * above, but it uses the usbcore scatter-gather library.
422 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
423 struct scatterlist *sg, int num_sg, unsigned int length,
424 unsigned int *act_len)
428 /* don't submit s-g requests during abort/disconnect processing */
429 if (us->flags & ABORTING_OR_DISCONNECTING)
430 return USB_STOR_XFER_ERROR;
432 /* initialize the scatter-gather request block */
433 US_DEBUGP("%s: xfer %u bytes, %d entries\n", __FUNCTION__,
435 result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
436 sg, num_sg, length, SLAB_NOIO);
438 US_DEBUGP("usb_sg_init returned %d\n", result);
439 return USB_STOR_XFER_ERROR;
442 /* since the block has been initialized successfully, it's now
443 * okay to cancel it */
444 set_bit(US_FLIDX_SG_ACTIVE, &us->flags);
446 /* did an abort/disconnect occur during the submission? */
447 if (us->flags & ABORTING_OR_DISCONNECTING) {
449 /* cancel the request, if it hasn't been cancelled already */
450 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) {
451 US_DEBUGP("-- cancelling sg request\n");
452 usb_sg_cancel(&us->current_sg);
456 /* wait for the completion of the transfer */
457 usb_sg_wait(&us->current_sg);
458 clear_bit(US_FLIDX_SG_ACTIVE, &us->flags);
460 result = us->current_sg.status;
462 *act_len = us->current_sg.bytes;
463 return interpret_urb_result(us, pipe, length, result,
464 us->current_sg.bytes);
468 * Transfer an entire SCSI command's worth of data payload over the bulk
471 * Note that this uses usb_stor_bulk_transfer_buf() and
472 * usb_stor_bulk_transfer_sglist() to achieve its goals --
473 * this function simply determines whether we're going to use
474 * scatter-gather or not, and acts appropriately.
476 int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
477 void *buf, unsigned int length_left, int use_sg, int *residual)
480 unsigned int partial;
482 /* are we scatter-gathering? */
484 /* use the usb core scatter-gather primitives */
485 result = usb_stor_bulk_transfer_sglist(us, pipe,
486 (struct scatterlist *) buf, use_sg,
487 length_left, &partial);
488 length_left -= partial;
490 /* no scatter-gather, just make the request */
491 result = usb_stor_bulk_transfer_buf(us, pipe, buf,
492 length_left, &partial);
493 length_left -= partial;
496 /* store the residual and return the error code */
498 *residual = length_left;
502 /***********************************************************************
504 ***********************************************************************/
506 /* Invoke the transport and basic error-handling/recovery methods
508 * This is used by the protocol layers to actually send the message to
509 * the device and receive the response.
511 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
516 /* send the command to the transport layer */
518 result = us->transport(srb, us);
520 /* if the command gets aborted by the higher layers, we need to
521 * short-circuit all other processing
523 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
524 US_DEBUGP("-- command was aborted\n");
525 srb->result = DID_ABORT << 16;
529 /* if there is a transport error, reset and don't auto-sense */
530 if (result == USB_STOR_TRANSPORT_ERROR) {
531 US_DEBUGP("-- transport indicates error, resetting\n");
532 srb->result = DID_ERROR << 16;
536 /* if the transport provided its own sense data, don't auto-sense */
537 if (result == USB_STOR_TRANSPORT_NO_SENSE) {
538 srb->result = SAM_STAT_CHECK_CONDITION;
542 srb->result = SAM_STAT_GOOD;
544 /* Determine if we need to auto-sense
546 * I normally don't use a flag like this, but it's almost impossible
547 * to understand what's going on here if I don't.
552 * If we're running the CB transport, which is incapable
553 * of determining status on its own, we will auto-sense
554 * unless the operation involved a data-in transfer. Devices
555 * can signal most data-in errors by stalling the bulk-in pipe.
557 if ((us->protocol == US_PR_CB || us->protocol == US_PR_DPCM_USB) &&
558 srb->sc_data_direction != DMA_FROM_DEVICE) {
559 US_DEBUGP("-- CB transport device requiring auto-sense\n");
564 * If we have a failure, we're going to do a REQUEST_SENSE
565 * automatically. Note that we differentiate between a command
566 * "failure" and an "error" in the transport mechanism.
568 if (result == USB_STOR_TRANSPORT_FAILED) {
569 US_DEBUGP("-- transport indicates command failure\n");
574 * A short transfer on a command where we don't expect it
575 * is unusual, but it doesn't mean we need to auto-sense.
577 if ((srb->resid > 0) &&
578 !((srb->cmnd[0] == REQUEST_SENSE) ||
579 (srb->cmnd[0] == INQUIRY) ||
580 (srb->cmnd[0] == MODE_SENSE) ||
581 (srb->cmnd[0] == LOG_SENSE) ||
582 (srb->cmnd[0] == MODE_SENSE_10))) {
583 US_DEBUGP("-- unexpectedly short transfer\n");
586 /* Now, if we need to do the auto-sense, let's do it */
587 if (need_auto_sense) {
589 void* old_request_buffer;
590 unsigned short old_sg;
591 unsigned old_request_bufflen;
592 unsigned char old_sc_data_direction;
593 unsigned char old_cmd_len;
594 unsigned char old_cmnd[MAX_COMMAND_SIZE];
597 US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
599 /* save the old command */
600 memcpy(old_cmnd, srb->cmnd, MAX_COMMAND_SIZE);
601 old_cmd_len = srb->cmd_len;
603 /* set the command and the LUN */
604 memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
605 srb->cmnd[0] = REQUEST_SENSE;
606 srb->cmnd[1] = old_cmnd[1] & 0xE0;
609 /* FIXME: we must do the protocol translation here */
610 if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI)
615 /* set the transfer direction */
616 old_sc_data_direction = srb->sc_data_direction;
617 srb->sc_data_direction = DMA_FROM_DEVICE;
619 /* use the new buffer we have */
620 old_request_buffer = srb->request_buffer;
621 srb->request_buffer = us->sensebuf;
623 /* set the buffer length for transfer */
624 old_request_bufflen = srb->request_bufflen;
625 srb->request_bufflen = US_SENSE_SIZE;
627 /* set up for no scatter-gather use */
628 old_sg = srb->use_sg;
631 /* issue the auto-sense command */
632 old_resid = srb->resid;
634 temp_result = us->transport(us->srb, us);
636 /* let's clean up right away */
637 memcpy(srb->sense_buffer, us->sensebuf, US_SENSE_SIZE);
638 srb->resid = old_resid;
639 srb->request_buffer = old_request_buffer;
640 srb->request_bufflen = old_request_bufflen;
641 srb->use_sg = old_sg;
642 srb->sc_data_direction = old_sc_data_direction;
643 srb->cmd_len = old_cmd_len;
644 memcpy(srb->cmnd, old_cmnd, MAX_COMMAND_SIZE);
646 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
647 US_DEBUGP("-- auto-sense aborted\n");
648 srb->result = DID_ABORT << 16;
651 if (temp_result != USB_STOR_TRANSPORT_GOOD) {
652 US_DEBUGP("-- auto-sense failure\n");
654 /* we skip the reset if this happens to be a
655 * multi-target device, since failure of an
656 * auto-sense is perfectly valid
658 srb->result = DID_ERROR << 16;
659 if (!(us->flags & US_FL_SCM_MULT_TARG))
664 US_DEBUGP("-- Result from auto-sense is %d\n", temp_result);
665 US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
666 srb->sense_buffer[0],
667 srb->sense_buffer[2] & 0xf,
668 srb->sense_buffer[12],
669 srb->sense_buffer[13]);
670 #ifdef CONFIG_USB_STORAGE_DEBUG
672 srb->sense_buffer[2] & 0xf,
673 srb->sense_buffer[12],
674 srb->sense_buffer[13]);
677 /* set the result so the higher layers expect this data */
678 srb->result = SAM_STAT_CHECK_CONDITION;
680 /* If things are really okay, then let's show that. Zero
681 * out the sense buffer so the higher layers won't realize
682 * we did an unsolicited auto-sense. */
683 if (result == USB_STOR_TRANSPORT_GOOD &&
684 /* Filemark 0, ignore EOM, ILI 0, no sense */
685 (srb->sense_buffer[2] & 0xaf) == 0 &&
687 srb->sense_buffer[12] == 0 &&
688 srb->sense_buffer[13] == 0) {
689 srb->result = SAM_STAT_GOOD;
690 srb->sense_buffer[0] = 0x0;
694 /* Did we transfer less than the minimum amount required? */
695 if (srb->result == SAM_STAT_GOOD &&
696 srb->request_bufflen - srb->resid < srb->underflow)
697 srb->result = (DID_ERROR << 16) | (SUGGEST_RETRY << 24);
701 /* Error and abort processing: try to resynchronize with the device
702 * by issuing a port reset. If that fails, try a class-specific
706 /* Let the SCSI layer know we are doing a reset, set the
707 * RESETTING bit, and clear the ABORTING bit so that the reset
709 scsi_lock(us_to_host(us));
710 usb_stor_report_bus_reset(us);
711 set_bit(US_FLIDX_RESETTING, &us->flags);
712 clear_bit(US_FLIDX_ABORTING, &us->flags);
713 scsi_unlock(us_to_host(us));
715 result = usb_stor_port_reset(us);
717 scsi_lock(us_to_host(us));
718 usb_stor_report_device_reset(us);
719 scsi_unlock(us_to_host(us));
720 us->transport_reset(us);
722 clear_bit(US_FLIDX_RESETTING, &us->flags);
725 /* Stop the current URB transfer */
726 void usb_stor_stop_transport(struct us_data *us)
728 US_DEBUGP("%s called\n", __FUNCTION__);
730 /* If the state machine is blocked waiting for an URB,
731 * let's wake it up. The test_and_clear_bit() call
732 * guarantees that if a URB has just been submitted,
733 * it won't be cancelled more than once. */
734 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) {
735 US_DEBUGP("-- cancelling URB\n");
736 usb_unlink_urb(us->current_urb);
739 /* If we are waiting for a scatter-gather operation, cancel it. */
740 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) {
741 US_DEBUGP("-- cancelling sg request\n");
742 usb_sg_cancel(&us->current_sg);
747 * Control/Bulk/Interrupt transport
750 int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us)
752 unsigned int transfer_length = srb->request_bufflen;
753 unsigned int pipe = 0;
757 /* let's send the command via the control pipe */
758 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
760 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
761 us->ifnum, srb->cmnd, srb->cmd_len);
763 /* check the return code for the command */
764 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
766 /* if we stalled the command, it means command failed */
767 if (result == USB_STOR_XFER_STALLED) {
768 return USB_STOR_TRANSPORT_FAILED;
771 /* Uh oh... serious problem here */
772 if (result != USB_STOR_XFER_GOOD) {
773 return USB_STOR_TRANSPORT_ERROR;
777 /* transfer the data payload for this command, if one exists*/
778 if (transfer_length) {
779 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
780 us->recv_bulk_pipe : us->send_bulk_pipe;
781 result = usb_stor_bulk_transfer_sg(us, pipe,
782 srb->request_buffer, transfer_length,
783 srb->use_sg, &srb->resid);
784 US_DEBUGP("CBI data stage result is 0x%x\n", result);
786 /* if we stalled the data transfer it means command failed */
787 if (result == USB_STOR_XFER_STALLED)
788 return USB_STOR_TRANSPORT_FAILED;
789 if (result > USB_STOR_XFER_STALLED)
790 return USB_STOR_TRANSPORT_ERROR;
794 result = usb_stor_intr_transfer(us, us->iobuf, 2);
795 US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n",
796 us->iobuf[0], us->iobuf[1]);
797 if (result != USB_STOR_XFER_GOOD)
798 return USB_STOR_TRANSPORT_ERROR;
800 /* UFI gives us ASC and ASCQ, like a request sense
802 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
803 * devices, so we ignore the information for those commands. Note
804 * that this means we could be ignoring a real error on these
805 * commands, but that can't be helped.
807 if (us->subclass == US_SC_UFI) {
808 if (srb->cmnd[0] == REQUEST_SENSE ||
809 srb->cmnd[0] == INQUIRY)
810 return USB_STOR_TRANSPORT_GOOD;
813 return USB_STOR_TRANSPORT_GOOD;
816 /* If not UFI, we interpret the data as a result code
817 * The first byte should always be a 0x0.
819 * Some bogus devices don't follow that rule. They stuff the ASC
820 * into the first byte -- so if it's non-zero, call it a failure.
823 US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n",
829 /* The second byte & 0x0F should be 0x0 for good, otherwise error */
830 switch (us->iobuf[1] & 0x0F) {
832 return USB_STOR_TRANSPORT_GOOD;
836 return USB_STOR_TRANSPORT_ERROR;
838 /* the CBI spec requires that the bulk pipe must be cleared
839 * following any data-in/out command failure (section 2.4.3.1.3)
843 usb_stor_clear_halt(us, pipe);
844 return USB_STOR_TRANSPORT_FAILED;
848 * Control/Bulk transport
850 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
852 unsigned int transfer_length = srb->request_bufflen;
856 /* let's send the command via the control pipe */
857 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
859 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
860 us->ifnum, srb->cmnd, srb->cmd_len);
862 /* check the return code for the command */
863 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
865 /* if we stalled the command, it means command failed */
866 if (result == USB_STOR_XFER_STALLED) {
867 return USB_STOR_TRANSPORT_FAILED;
870 /* Uh oh... serious problem here */
871 if (result != USB_STOR_XFER_GOOD) {
872 return USB_STOR_TRANSPORT_ERROR;
876 /* transfer the data payload for this command, if one exists*/
877 if (transfer_length) {
878 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
879 us->recv_bulk_pipe : us->send_bulk_pipe;
880 result = usb_stor_bulk_transfer_sg(us, pipe,
881 srb->request_buffer, transfer_length,
882 srb->use_sg, &srb->resid);
883 US_DEBUGP("CB data stage result is 0x%x\n", result);
885 /* if we stalled the data transfer it means command failed */
886 if (result == USB_STOR_XFER_STALLED)
887 return USB_STOR_TRANSPORT_FAILED;
888 if (result > USB_STOR_XFER_STALLED)
889 return USB_STOR_TRANSPORT_ERROR;
893 /* NOTE: CB does not have a status stage. Silly, I know. So
894 * we have to catch this at a higher level.
896 return USB_STOR_TRANSPORT_GOOD;
900 * Bulk only transport
903 /* Determine what the maximum LUN supported is */
904 int usb_stor_Bulk_max_lun(struct us_data *us)
908 /* issue the command */
910 result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
912 USB_DIR_IN | USB_TYPE_CLASS |
914 0, us->ifnum, us->iobuf, 1, HZ);
916 US_DEBUGP("GetMaxLUN command result is %d, data is %d\n",
917 result, us->iobuf[0]);
919 /* if we have a successful request, return the result */
924 * Some devices (i.e. Iomega Zip100) need this -- apparently
925 * the bulk pipes get STALLed when the GetMaxLUN request is
926 * processed. This is, in theory, harmless to all other devices
927 * (regardless of if they stall or not).
929 if (result == -EPIPE) {
930 usb_stor_clear_halt(us, us->recv_bulk_pipe);
931 usb_stor_clear_halt(us, us->send_bulk_pipe);
935 * Some devices don't like GetMaxLUN. They may STALL the control
936 * pipe, they may return a zero-length result, they may do nothing at
937 * all and timeout, or they may fail in even more bizarrely creative
938 * ways. In these cases the best approach is to use the default
939 * value: only one LUN.
944 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
946 struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
947 struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
948 unsigned int transfer_length = srb->request_bufflen;
949 unsigned int residue;
953 unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
955 /* Take care of BULK32 devices; set extra byte to 0 */
956 if ( unlikely(us->flags & US_FL_BULK32)) {
961 /* set up the command wrapper */
962 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
963 bcb->DataTransferLength = cpu_to_le32(transfer_length);
964 bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0;
965 bcb->Tag = ++us->tag;
966 bcb->Lun = srb->device->lun;
967 if (us->flags & US_FL_SCM_MULT_TARG)
968 bcb->Lun |= srb->device->id << 4;
969 bcb->Length = srb->cmd_len;
971 /* copy the command payload */
972 memset(bcb->CDB, 0, sizeof(bcb->CDB));
973 memcpy(bcb->CDB, srb->cmnd, bcb->Length);
975 /* send it to out endpoint */
976 US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
977 le32_to_cpu(bcb->Signature), bcb->Tag,
978 le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
979 (bcb->Lun >> 4), (bcb->Lun & 0x0F),
981 result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
983 US_DEBUGP("Bulk command transfer result=%d\n", result);
984 if (result != USB_STOR_XFER_GOOD)
985 return USB_STOR_TRANSPORT_ERROR;
988 /* send/receive data payload, if there is any */
990 /* Some USB-IDE converter chips need a 100us delay between the
991 * command phase and the data phase. Some devices need a little
992 * more than that, probably because of clock rate inaccuracies. */
993 if (unlikely(us->flags & US_FL_GO_SLOW))
996 if (transfer_length) {
997 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
998 us->recv_bulk_pipe : us->send_bulk_pipe;
999 result = usb_stor_bulk_transfer_sg(us, pipe,
1000 srb->request_buffer, transfer_length,
1001 srb->use_sg, &srb->resid);
1002 US_DEBUGP("Bulk data transfer result 0x%x\n", result);
1003 if (result == USB_STOR_XFER_ERROR)
1004 return USB_STOR_TRANSPORT_ERROR;
1006 /* If the device tried to send back more data than the
1007 * amount requested, the spec requires us to transfer
1008 * the CSW anyway. Since there's no point retrying the
1009 * the command, we'll return fake sense data indicating
1010 * Illegal Request, Invalid Field in CDB.
1012 if (result == USB_STOR_XFER_LONG)
1016 /* See flow chart on pg 15 of the Bulk Only Transport spec for
1017 * an explanation of how this code works.
1020 /* get CSW for device status */
1021 US_DEBUGP("Attempting to get CSW...\n");
1022 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1023 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1025 /* Some broken devices add unnecessary zero-length packets to the
1026 * end of their data transfers. Such packets show up as 0-length
1027 * CSWs. If we encounter such a thing, try to read the CSW again.
1029 if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
1030 US_DEBUGP("Received 0-length CSW; retrying...\n");
1031 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1032 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1035 /* did the attempt to read the CSW fail? */
1036 if (result == USB_STOR_XFER_STALLED) {
1038 /* get the status again */
1039 US_DEBUGP("Attempting to get CSW (2nd try)...\n");
1040 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1041 bcs, US_BULK_CS_WRAP_LEN, NULL);
1044 /* if we still have a failure at this point, we're in trouble */
1045 US_DEBUGP("Bulk status result = %d\n", result);
1046 if (result != USB_STOR_XFER_GOOD)
1047 return USB_STOR_TRANSPORT_ERROR;
1049 /* check bulk status */
1050 residue = le32_to_cpu(bcs->Residue);
1051 US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
1052 le32_to_cpu(bcs->Signature), bcs->Tag,
1053 residue, bcs->Status);
1054 if (bcs->Tag != us->tag || bcs->Status > US_BULK_STAT_PHASE) {
1055 US_DEBUGP("Bulk logical error\n");
1056 return USB_STOR_TRANSPORT_ERROR;
1059 /* Some broken devices report odd signatures, so we do not check them
1060 * for validity against the spec. We store the first one we see,
1061 * and check subsequent transfers for validity against this signature.
1063 if (!us->bcs_signature) {
1064 us->bcs_signature = bcs->Signature;
1065 if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
1066 US_DEBUGP("Learnt BCS signature 0x%08X\n",
1067 le32_to_cpu(us->bcs_signature));
1068 } else if (bcs->Signature != us->bcs_signature) {
1069 US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n",
1070 le32_to_cpu(bcs->Signature),
1071 le32_to_cpu(us->bcs_signature));
1072 return USB_STOR_TRANSPORT_ERROR;
1075 /* try to compute the actual residue, based on how much data
1076 * was really transferred and what the device tells us */
1078 if (!(us->flags & US_FL_IGNORE_RESIDUE)) {
1079 residue = min(residue, transfer_length);
1080 srb->resid = max(srb->resid, (int) residue);
1084 /* based on the status code, we report good or bad */
1085 switch (bcs->Status) {
1086 case US_BULK_STAT_OK:
1087 /* device babbled -- return fake sense data */
1089 memcpy(srb->sense_buffer,
1090 usb_stor_sense_invalidCDB,
1091 sizeof(usb_stor_sense_invalidCDB));
1092 return USB_STOR_TRANSPORT_NO_SENSE;
1095 /* command good -- note that data could be short */
1096 return USB_STOR_TRANSPORT_GOOD;
1098 case US_BULK_STAT_FAIL:
1099 /* command failed */
1100 return USB_STOR_TRANSPORT_FAILED;
1102 case US_BULK_STAT_PHASE:
1103 /* phase error -- note that a transport reset will be
1104 * invoked by the invoke_transport() function
1106 return USB_STOR_TRANSPORT_ERROR;
1109 /* we should never get here, but if we do, we're in trouble */
1110 return USB_STOR_TRANSPORT_ERROR;
1113 /***********************************************************************
1115 ***********************************************************************/
1117 /* This is the common part of the device reset code.
1119 * It's handy that every transport mechanism uses the control endpoint for
1122 * Basically, we send a reset with a 5-second timeout, so we don't get
1123 * jammed attempting to do the reset.
1125 static int usb_stor_reset_common(struct us_data *us,
1126 u8 request, u8 requesttype,
1127 u16 value, u16 index, void *data, u16 size)
1132 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
1133 US_DEBUGP("No reset during disconnect\n");
1137 result = usb_stor_control_msg(us, us->send_ctrl_pipe,
1138 request, requesttype, value, index, data, size,
1141 US_DEBUGP("Soft reset failed: %d\n", result);
1145 /* Give the device some time to recover from the reset,
1146 * but don't delay disconnect processing. */
1147 wait_event_interruptible_timeout(us->delay_wait,
1148 test_bit(US_FLIDX_DISCONNECTING, &us->flags),
1150 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
1151 US_DEBUGP("Reset interrupted by disconnect\n");
1155 US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n");
1156 result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
1158 US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n");
1159 result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
1161 /* return a result code based on the result of the clear-halts */
1165 US_DEBUGP("Soft reset failed\n");
1167 US_DEBUGP("Soft reset done\n");
1171 /* This issues a CB[I] Reset to the device in question
1173 #define CB_RESET_CMD_SIZE 12
1175 int usb_stor_CB_reset(struct us_data *us)
1177 US_DEBUGP("%s called\n", __FUNCTION__);
1179 memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
1180 us->iobuf[0] = SEND_DIAGNOSTIC;
1182 return usb_stor_reset_common(us, US_CBI_ADSC,
1183 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1184 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
1187 /* This issues a Bulk-only Reset to the device in question, including
1188 * clearing the subsequent endpoint halts that may occur.
1190 int usb_stor_Bulk_reset(struct us_data *us)
1192 US_DEBUGP("%s called\n", __FUNCTION__);
1194 return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
1195 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1196 0, us->ifnum, NULL, 0);
1199 /* Issue a USB port reset to the device. But don't do anything if
1200 * there's more than one interface in the device, so that other users
1201 * are not affected. */
1202 int usb_stor_port_reset(struct us_data *us)
1206 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
1208 US_DEBUGP("No reset during disconnect\n");
1209 } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) {
1211 US_DEBUGP("Refusing to reset a multi-interface device\n");
1214 usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
1216 US_DEBUGP("unable to lock device for reset: %d\n",
1219 result = usb_reset_device(us->pusb_dev);
1221 usb_unlock_device(us->pusb_dev);
1222 US_DEBUGP("usb_reset_device returns %d\n", result);