// SPDX-License-Identifier: GPL-2.0+ /* * Driver for USB Mass Storage compliant devices * * Current development and maintenance by: * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net) * * Developed with the assistance of: * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org) * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov) * (c) 2002 Alan Stern <stern@rowland.org> * * Initial work by: * (c) 1999 Michael Gee (michael@linuxspecific.com) * * This driver is based on the 'USB Mass Storage Class' document. This * describes in detail the protocol used to communicate with such * devices. Clearly, the designers had SCSI and ATAPI commands in * mind when they created this document. The commands are all very * similar to commands in the SCSI-II and ATAPI specifications. * * It is important to note that in a number of cases this class * exhibits class-specific exemptions from the USB specification. * Notably the usage of NAK, STALL and ACK differs from the norm, in * that they are used to communicate wait, failed and OK on commands. * * Also, for certain devices, the interrupt endpoint is used to convey * status of a command.
*/
/*********************************************************************** * Data transfer routines
***********************************************************************/
/* * This is subtle, so pay attention: * --------------------------------- * We're very concerned about races with a command abort. Hanging this code * is a sure fire way to hang the kernel. (Note that this discussion applies * only to transactions resulting from a scsi queued-command, since only * these transactions are subject to a scsi abort. Other transactions, such * as those occurring during device-specific initialization, must be handled * by a separate code path.) * * The abort function (usb_storage_command_abort() in scsiglue.c) first * sets the machine state and the ABORTING bit in us->dflags to prevent * new URBs from being submitted. It then calls usb_stor_stop_transport() * below, which atomically tests-and-clears the URB_ACTIVE bit in us->dflags * to see if the current_urb needs to be stopped. Likewise, the SG_ACTIVE * bit is tested to see if the current_sg scatter-gather request needs to be * stopped. The timeout callback routine does much the same thing. * * When a disconnect occurs, the DISCONNECTING bit in us->dflags is set to * prevent new URBs from being submitted, and usb_stor_stop_transport() is * called to stop any ongoing requests. * * The submit function first verifies that the submitting is allowed * (neither ABORTING nor DISCONNECTING bits are set) and that the submit * completes without errors, and only then sets the URB_ACTIVE bit. This * prevents the stop_transport() function from trying to cancel the URB * while the submit call is underway. Next, the submit function must test * the flags to see if an abort or disconnect occurred during the submission * or before the URB_ACTIVE bit was set. If so, it's essential to cancel * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit * is still set). Either way, the function must then wait for the URB to * finish. Note that the URB can still be in progress even after a call to * usb_unlink_urb() returns. * * The idea is that (1) once the ABORTING or DISCONNECTING bit is set, * either the stop_transport() function or the submitting function * is guaranteed to call usb_unlink_urb() for an active URB, * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being * called more than once or from being called during usb_submit_urb().
*/
/* * This is the completion handler which will wake us up when an URB * completes.
*/ staticvoid usb_stor_blocking_completion(struct urb *urb)
{ struct completion *urb_done_ptr = urb->context;
complete(urb_done_ptr);
}
/* * This is the common part of the URB message submission code * * All URBs from the usb-storage driver involved in handling a queued scsi * command _must_ pass through this function (or something like it) for the * abort mechanisms to work properly.
*/ staticint usb_stor_msg_common(struct us_data *us, int timeout)
{ struct completion urb_done; long timeleft; int status;
/* don't submit URBs during abort processing */ if (test_bit(US_FLIDX_ABORTING, &us->dflags)) return -EIO;
/* set up data structures for the wakeup system */
init_completion(&urb_done);
/* fill the common fields in the URB */
us->current_urb->context = &urb_done;
us->current_urb->transfer_flags = 0;
/* * we assume that if transfer_buffer isn't us->iobuf then it * hasn't been mapped for DMA. Yes, this is clunky, but it's * easier than always having the caller tell us whether the * transfer buffer has already been mapped.
*/ if (us->current_urb->transfer_buffer == us->iobuf)
us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
us->current_urb->transfer_dma = us->iobuf_dma;
/* submit the URB */
status = usb_submit_urb(us->current_urb, GFP_NOIO); if (status) { /* something went wrong */ return status;
}
/* * since the URB has been submitted successfully, it's now okay * to cancel it
*/
set_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
/* did an abort occur during the submission? */ if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
/* cancel the URB, if it hasn't been cancelled already */ if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
usb_stor_dbg(us, "-- cancelling URB\n");
usb_unlink_urb(us->current_urb);
}
}
/* wait for the completion of the URB */
timeleft = wait_for_completion_interruptible_timeout(
&urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
/* return the URB status */ return us->current_urb->status;
}
/* * Transfer one control message, with timeouts, and allowing early * termination. Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
*/ int usb_stor_control_msg(struct us_data *us, unsignedint pipe,
u8 request, u8 requesttype, u16 value, u16 index, void *data, u16 size, int timeout)
{ int status;
/* fill in the devrequest structure */
us->cr->bRequestType = requesttype;
us->cr->bRequest = request;
us->cr->wValue = cpu_to_le16(value);
us->cr->wIndex = cpu_to_le16(index);
us->cr->wLength = cpu_to_le16(size);
/* fill and submit the URB */
usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
(unsignedchar*) us->cr, data, size,
usb_stor_blocking_completion, NULL);
status = usb_stor_msg_common(us, timeout);
/* return the actual length of the data transferred if no error */ if (status == 0)
status = us->current_urb->actual_length; return status;
}
EXPORT_SYMBOL_GPL(usb_stor_control_msg);
/* * This is a version of usb_clear_halt() that allows early termination and * doesn't read the status from the device -- this is because some devices * crash their internal firmware when the status is requested after a halt. * * A definitive list of these 'bad' devices is too difficult to maintain or * make complete enough to be useful. This problem was first observed on the * Hagiwara FlashGate DUAL unit. However, bus traces reveal that neither * MacOS nor Windows checks the status after clearing a halt. * * Since many vendors in this space limit their testing to interoperability * with these two OSes, specification violations like this one are common.
*/ int usb_stor_clear_halt(struct us_data *us, unsignedint pipe)
{ int result; int endp = usb_pipeendpoint(pipe);
/* * Interpret the results of a URB transfer * * This function prints appropriate debugging messages, clears halts on * non-control endpoints, and translates the status to the corresponding * USB_STOR_XFER_xxx return code.
*/ staticint interpret_urb_result(struct us_data *us, unsignedint pipe, unsignedint length, int result, unsignedint partial)
{
usb_stor_dbg(us, "Status code %d; transferred %u/%u\n",
result, partial, length); switch (result) {
/* no error code; did we send all the data? */ case 0: if (partial != length) {
usb_stor_dbg(us, "-- short transfer\n"); return USB_STOR_XFER_SHORT;
}
usb_stor_dbg(us, "-- transfer complete\n"); return USB_STOR_XFER_GOOD;
/* stalled */ case -EPIPE: /* * for control endpoints, (used by CB[I]) a stall indicates * a failed command
*/ if (usb_pipecontrol(pipe)) {
usb_stor_dbg(us, "-- stall on control pipe\n"); return USB_STOR_XFER_STALLED;
}
/* for other sorts of endpoint, clear the stall */
usb_stor_dbg(us, "clearing endpoint halt for pipe 0x%x\n",
pipe); if (usb_stor_clear_halt(us, pipe) < 0) return USB_STOR_XFER_ERROR; return USB_STOR_XFER_STALLED;
/* babble - the device tried to send more than we wanted to read */ case -EOVERFLOW:
usb_stor_dbg(us, "-- babble\n"); return USB_STOR_XFER_LONG;
/* the transfer was cancelled by abort, disconnect, or timeout */ case -ECONNRESET:
usb_stor_dbg(us, "-- transfer cancelled\n"); return USB_STOR_XFER_ERROR;
/* short scatter-gather read transfer */ case -EREMOTEIO:
usb_stor_dbg(us, "-- short read transfer\n"); return USB_STOR_XFER_SHORT;
/* abort or disconnect in progress */ case -EIO:
usb_stor_dbg(us, "-- abort or disconnect in progress\n"); return USB_STOR_XFER_ERROR;
/* the catch-all error case */ default:
usb_stor_dbg(us, "-- unknown error\n"); return USB_STOR_XFER_ERROR;
}
}
/* * Transfer one control message, without timeouts, but allowing early * termination. Return codes are USB_STOR_XFER_xxx.
*/ int usb_stor_ctrl_transfer(struct us_data *us, unsignedint pipe,
u8 request, u8 requesttype, u16 value, u16 index, void *data, u16 size)
{ int result;
/* fill in the devrequest structure */
us->cr->bRequestType = requesttype;
us->cr->bRequest = request;
us->cr->wValue = cpu_to_le16(value);
us->cr->wIndex = cpu_to_le16(index);
us->cr->wLength = cpu_to_le16(size);
/* fill and submit the URB */
usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
(unsignedchar*) us->cr, data, size,
usb_stor_blocking_completion, NULL);
result = usb_stor_msg_common(us, 0);
/* * Receive one interrupt buffer, without timeouts, but allowing early * termination. Return codes are USB_STOR_XFER_xxx. * * This routine always uses us->recv_intr_pipe as the pipe and * us->ep_bInterval as the interrupt interval.
*/ staticint usb_stor_intr_transfer(struct us_data *us, void *buf, unsignedint length)
{ int result; unsignedint pipe = us->recv_intr_pipe; unsignedint maxp;
usb_stor_dbg(us, "xfer %u bytes\n", length);
/* calculate the max packet size */
maxp = usb_maxpacket(us->pusb_dev, pipe); if (maxp > length)
maxp = length;
/* fill and submit the URB */
usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
maxp, usb_stor_blocking_completion, NULL,
us->ep_bInterval);
result = usb_stor_msg_common(us, 0);
/* * Transfer one buffer via bulk pipe, without timeouts, but allowing early * termination. Return codes are USB_STOR_XFER_xxx. If the bulk pipe * stalls during the transfer, the halt is automatically cleared.
*/ int usb_stor_bulk_transfer_buf(struct us_data *us, unsignedint pipe, void *buf, unsignedint length, unsignedint *act_len)
{ int result;
usb_stor_dbg(us, "xfer %u bytes\n", length);
/* fill and submit the URB */
usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
usb_stor_blocking_completion, NULL);
result = usb_stor_msg_common(us, 0);
/* store the actual length of the data transferred */ if (act_len)
*act_len = us->current_urb->actual_length; return interpret_urb_result(us, pipe, length, result,
us->current_urb->actual_length);
}
EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_buf);
/* * Transfer a scatter-gather list via bulk transfer * * This function does basically the same thing as usb_stor_bulk_transfer_buf() * above, but it uses the usbcore scatter-gather library.
*/ staticint usb_stor_bulk_transfer_sglist(struct us_data *us, unsignedint pipe, struct scatterlist *sg, int num_sg, unsignedint length, unsignedint *act_len)
{ int result;
/* don't submit s-g requests during abort processing */ if (test_bit(US_FLIDX_ABORTING, &us->dflags)) goto usb_stor_xfer_error;
/* initialize the scatter-gather request block */
usb_stor_dbg(us, "xfer %u bytes, %d entries\n", length, num_sg);
result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
sg, num_sg, length, GFP_NOIO); if (result) {
usb_stor_dbg(us, "usb_sg_init returned %d\n", result); goto usb_stor_xfer_error;
}
/* * since the block has been initialized successfully, it's now * okay to cancel it
*/
set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
/* did an abort occur during the submission? */ if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
/* cancel the request, if it hasn't been cancelled already */ if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
usb_stor_dbg(us, "-- cancelling sg request\n");
usb_sg_cancel(&us->current_sg);
}
}
/* wait for the completion of the transfer */
usb_sg_wait(&us->current_sg);
clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
result = us->current_sg.status; if (act_len)
*act_len = us->current_sg.bytes; return interpret_urb_result(us, pipe, length, result,
us->current_sg.bytes);
usb_stor_xfer_error: if (act_len)
*act_len = 0; return USB_STOR_XFER_ERROR;
}
/* * Common used function. Transfer a complete command * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
*/ int usb_stor_bulk_srb(struct us_data* us, unsignedint pipe, struct scsi_cmnd* srb)
{ unsignedint partial; int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
scsi_sg_count(srb), scsi_bufflen(srb),
&partial);
/* * Transfer an entire SCSI command's worth of data payload over the bulk * pipe. * * Note that this uses usb_stor_bulk_transfer_buf() and * usb_stor_bulk_transfer_sglist() to achieve its goals -- * this function simply determines whether we're going to use * scatter-gather or not, and acts appropriately.
*/ int usb_stor_bulk_transfer_sg(struct us_data* us, unsignedint pipe, void *buf, unsignedint length_left, int use_sg, int *residual)
{ int result; unsignedint partial;
/* are we scatter-gathering? */ if (use_sg) { /* use the usb core scatter-gather primitives */
result = usb_stor_bulk_transfer_sglist(us, pipe,
(struct scatterlist *) buf, use_sg,
length_left, &partial);
length_left -= partial;
} else { /* no scatter-gather, just make the request */
result = usb_stor_bulk_transfer_buf(us, pipe, buf,
length_left, &partial);
length_left -= partial;
}
/* store the residual and return the error code */ if (residual)
*residual = length_left; return result;
}
EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_sg);
/*********************************************************************** * Transport routines
***********************************************************************/
/* * There are so many devices that report the capacity incorrectly, * this routine was written to counteract some of the resulting * problems.
*/ staticvoid last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb)
{ struct gendisk *disk; struct scsi_disk *sdkp;
u32 sector;
/* To Report "Medium Error: Record Not Found */ staticconstunsignedchar record_not_found[18] = {
[0] = 0x70, /* current error */
[2] = MEDIUM_ERROR, /* = 0x03 */
[7] = 0x0a, /* additional length */
[12] = 0x14 /* Record Not Found */
};
/* * If last-sector problems can't occur, whether because the * capacity was already decremented or because the device is * known to report the correct capacity, then we don't need * to do anything.
*/ if (!us->use_last_sector_hacks) return;
/* Was this command a READ(10) or a WRITE(10)? */ if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10) goto done;
/* Did this command access the last sector? */
sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) |
(srb->cmnd[4] << 8) | (srb->cmnd[5]);
disk = scsi_cmd_to_rq(srb)->q->disk; if (!disk) goto done;
sdkp = scsi_disk(disk); if (!sdkp) goto done; if (sector + 1 != sdkp->capacity) goto done;
if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) {
/* * The command succeeded. We know this device doesn't * have the last-sector bug, so stop checking it.
*/
us->use_last_sector_hacks = 0;
} else { /* * The command failed. Allow up to 3 retries in case this * is some normal sort of failure. After that, assume the * capacity is wrong and we're trying to access the sector * beyond the end. Replace the result code and sense data * with values that will cause the SCSI core to fail the * command immediately, instead of going into an infinite * (or even just a very long) retry loop.
*/ if (++us->last_sector_retries < 3) return;
srb->result = SAM_STAT_CHECK_CONDITION;
memcpy(srb->sense_buffer, record_not_found, sizeof(record_not_found));
}
done: /* * Don't reset the retry counter for TEST UNIT READY commands, * because they get issued after device resets which might be * caused by a failed last-sector access.
*/ if (srb->cmnd[0] != TEST_UNIT_READY)
us->last_sector_retries = 0;
}
/* * Invoke the transport and basic error-handling/recovery methods * * This is used by the protocol layers to actually send the message to * the device and receive the response.
*/ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
{ int need_auto_sense; int result;
/* send the command to the transport layer */
scsi_set_resid(srb, 0);
result = us->transport(srb, us);
/* * if the command gets aborted by the higher layers, we need to * short-circuit all other processing
*/ if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
usb_stor_dbg(us, "-- command was aborted\n");
srb->result = DID_ABORT << 16; goto Handle_Errors;
}
/* if there is a transport error, reset and don't auto-sense */ if (result == USB_STOR_TRANSPORT_ERROR) {
usb_stor_dbg(us, "-- transport indicates error, resetting\n");
srb->result = DID_ERROR << 16; goto Handle_Errors;
}
/* if the transport provided its own sense data, don't auto-sense */ if (result == USB_STOR_TRANSPORT_NO_SENSE) {
srb->result = SAM_STAT_CHECK_CONDITION;
last_sector_hacks(us, srb); return;
}
srb->result = SAM_STAT_GOOD;
/* * Determine if we need to auto-sense * * I normally don't use a flag like this, but it's almost impossible * to understand what's going on here if I don't.
*/
need_auto_sense = 0;
/* * If we're running the CB transport, which is incapable * of determining status on its own, we will auto-sense * unless the operation involved a data-in transfer. Devices * can signal most data-in errors by stalling the bulk-in pipe.
*/ if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_DPCM_USB) &&
srb->sc_data_direction != DMA_FROM_DEVICE) {
usb_stor_dbg(us, "-- CB transport device requiring auto-sense\n");
need_auto_sense = 1;
}
/* Some devices (Kindle) require another command after SYNC CACHE */ if ((us->fflags & US_FL_SENSE_AFTER_SYNC) &&
srb->cmnd[0] == SYNCHRONIZE_CACHE) {
usb_stor_dbg(us, "-- sense after SYNC CACHE\n");
need_auto_sense = 1;
}
/* * If we have a failure, we're going to do a REQUEST_SENSE * automatically. Note that we differentiate between a command * "failure" and an "error" in the transport mechanism.
*/ if (result == USB_STOR_TRANSPORT_FAILED) {
usb_stor_dbg(us, "-- transport indicates command failure\n");
need_auto_sense = 1;
}
/* * Determine if this device is SAT by seeing if the * command executed successfully. Otherwise we'll have * to wait for at least one CHECK_CONDITION to determine * SANE_SENSE support
*/ if (unlikely((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
result == USB_STOR_TRANSPORT_GOOD &&
!(us->fflags & US_FL_SANE_SENSE) &&
!(us->fflags & US_FL_BAD_SENSE) &&
!(srb->cmnd[2] & 0x20))) {
usb_stor_dbg(us, "-- SAT supported, increasing auto-sense\n");
us->fflags |= US_FL_SANE_SENSE;
}
/* * A short transfer on a command where we don't expect it * is unusual, but it doesn't mean we need to auto-sense.
*/ if ((scsi_get_resid(srb) > 0) &&
!((srb->cmnd[0] == REQUEST_SENSE) ||
(srb->cmnd[0] == INQUIRY) ||
(srb->cmnd[0] == MODE_SENSE) ||
(srb->cmnd[0] == LOG_SENSE) ||
(srb->cmnd[0] == MODE_SENSE_10))) {
usb_stor_dbg(us, "-- unexpectedly short transfer\n");
}
/* Now, if we need to do the auto-sense, let's do it */ if (need_auto_sense) { int temp_result; struct scsi_eh_save ses; int sense_size = US_SENSE_SIZE; struct scsi_sense_hdr sshdr; const u8 *scdd;
u8 fm_ili;
/* device supports and needs bigger sense buffer */ if (us->fflags & US_FL_SANE_SENSE)
sense_size = ~0;
Retry_Sense:
usb_stor_dbg(us, "Issuing auto-REQUEST_SENSE\n");
/* FIXME: we must do the protocol translation here */ if (us->subclass == USB_SC_RBC || us->subclass == USB_SC_SCSI ||
us->subclass == USB_SC_CYP_ATACB)
srb->cmd_len = 6; else
srb->cmd_len = 12;
/* If SANE_SENSE caused this problem, disable it */ if (sense_size != US_SENSE_SIZE) {
us->fflags &= ~US_FL_SANE_SENSE;
us->fflags |= US_FL_BAD_SENSE;
} goto Handle_Errors;
}
/* * Some devices claim to support larger sense but fail when * trying to request it. When a transport failure happens * using US_FS_SANE_SENSE, we always retry with a standard * (small) sense request. This fixes some USB GSM modems
*/ if (temp_result == USB_STOR_TRANSPORT_FAILED &&
sense_size != US_SENSE_SIZE) {
usb_stor_dbg(us, "-- auto-sense failure, retry small sense\n");
sense_size = US_SENSE_SIZE;
us->fflags &= ~US_FL_SANE_SENSE;
us->fflags |= US_FL_BAD_SENSE; goto Retry_Sense;
}
/* Other failures */ if (temp_result != USB_STOR_TRANSPORT_GOOD) {
usb_stor_dbg(us, "-- auto-sense failure\n");
/* * we skip the reset if this happens to be a * multi-target device, since failure of an * auto-sense is perfectly valid
*/
srb->result = DID_ERROR << 16; if (!(us->fflags & US_FL_SCM_MULT_TARG)) goto Handle_Errors; return;
}
/* * If the sense data returned is larger than 18-bytes then we * assume this device supports requesting more in the future. * The response code must be 70h through 73h inclusive.
*/ if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
!(us->fflags & US_FL_SANE_SENSE) &&
!(us->fflags & US_FL_BAD_SENSE) &&
(srb->sense_buffer[0] & 0x7C) == 0x70) {
usb_stor_dbg(us, "-- SANE_SENSE support enabled\n");
us->fflags |= US_FL_SANE_SENSE;
/* * Indicate to the user that we truncated their sense * because we didn't know it supported larger sense.
*/
usb_stor_dbg(us, "-- Sense data truncated to %i from %i\n",
US_SENSE_SIZE,
srb->sense_buffer[7] + 8);
srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
}
/* * We often get empty sense data. This could indicate that * everything worked or that there was an unspecified * problem. We have to decide which.
*/ if (sshdr.sense_key == 0 && sshdr.asc == 0 && sshdr.ascq == 0 &&
fm_ili == 0) { /* * If things are really okay, then let's show that. * Zero out the sense buffer so the higher layers * won't realize we did an unsolicited auto-sense.
*/ if (result == USB_STOR_TRANSPORT_GOOD) {
srb->result = SAM_STAT_GOOD;
srb->sense_buffer[0] = 0x0;
}
/* * ATA-passthru commands use sense data to report * the command completion status, and often devices * return Check Condition status when nothing is * wrong.
*/ elseif (srb->cmnd[0] == ATA_16 ||
srb->cmnd[0] == ATA_12) { /* leave the data alone */
}
/* * If there was a problem, report an unspecified * hardware error to prevent the higher layers from * entering an infinite retry loop.
*/ else {
srb->result = DID_ERROR << 16; if ((sshdr.response_code & 0x72) == 0x72)
srb->sense_buffer[1] = HARDWARE_ERROR; else
srb->sense_buffer[2] = HARDWARE_ERROR;
}
}
}
/* * Some devices don't work or return incorrect data the first * time they get a READ(10) command, or for the first READ(10) * after a media change. If the INITIAL_READ10 flag is set, * keep track of whether READ(10) commands succeed. If the * previous one succeeded and this one failed, set the REDO_READ10 * flag to force a retry.
*/ if (unlikely((us->fflags & US_FL_INITIAL_READ10) &&
srb->cmnd[0] == READ_10)) { if (srb->result == SAM_STAT_GOOD) {
set_bit(US_FLIDX_READ10_WORKED, &us->dflags);
} elseif (test_bit(US_FLIDX_READ10_WORKED, &us->dflags)) {
clear_bit(US_FLIDX_READ10_WORKED, &us->dflags);
set_bit(US_FLIDX_REDO_READ10, &us->dflags);
}
/* * Next, if the REDO_READ10 flag is set, return a result * code that will cause the SCSI core to retry the READ(10) * command immediately.
*/ if (test_bit(US_FLIDX_REDO_READ10, &us->dflags)) {
clear_bit(US_FLIDX_REDO_READ10, &us->dflags);
srb->result = DID_IMM_RETRY << 16;
srb->sense_buffer[0] = 0;
}
}
/* Did we transfer less than the minimum amount required? */ if ((srb->result == SAM_STAT_GOOD || srb->sense_buffer[2] == 0) &&
scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
srb->result = DID_ERROR << 16;
last_sector_hacks(us, srb); return;
/* * Error and abort processing: try to resynchronize with the device * by issuing a port reset. If that fails, try a class-specific * device reset.
*/
Handle_Errors:
/* * Set the RESETTING bit, and clear the ABORTING bit so that * the reset may proceed.
*/
scsi_lock(us_to_host(us));
set_bit(US_FLIDX_RESETTING, &us->dflags);
clear_bit(US_FLIDX_ABORTING, &us->dflags);
scsi_unlock(us_to_host(us));
/* * We must release the device lock because the pre_reset routine * will want to acquire it.
*/
mutex_unlock(&us->dev_mutex);
result = usb_stor_port_reset(us);
mutex_lock(&us->dev_mutex);
/* Stop the current URB transfer */ void usb_stor_stop_transport(struct us_data *us)
{ /* * If the state machine is blocked waiting for an URB, * let's wake it up. The test_and_clear_bit() call * guarantees that if a URB has just been submitted, * it won't be cancelled more than once.
*/ if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
usb_stor_dbg(us, "-- cancelling URB\n");
usb_unlink_urb(us->current_urb);
}
/* If we are waiting for a scatter-gather operation, cancel it. */ if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
usb_stor_dbg(us, "-- cancelling sg request\n");
usb_sg_cancel(&us->current_sg);
}
}
/* * Control/Bulk and Control/Bulk/Interrupt transport
*/
int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
{ unsignedint transfer_length = scsi_bufflen(srb); unsignedint pipe = 0; int result;
/* COMMAND STAGE */ /* let's send the command via the control pipe */ /* * Command is sometime (f.e. after scsi_eh_prep_cmnd) on the stack. * Stack may be vmallocated. So no DMA for us. Make a copy.
*/
memcpy(us->iobuf, srb->cmnd, srb->cmd_len);
result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
US_CBI_ADSC,
USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
us->ifnum, us->iobuf, srb->cmd_len);
/* check the return code for the command */
usb_stor_dbg(us, "Call to usb_stor_ctrl_transfer() returned %d\n",
result);
/* if we stalled the command, it means command failed */ if (result == USB_STOR_XFER_STALLED) { return USB_STOR_TRANSPORT_FAILED;
}
/* Uh oh... serious problem here */ if (result != USB_STOR_XFER_GOOD) { return USB_STOR_TRANSPORT_ERROR;
}
/* DATA STAGE */ /* transfer the data payload for this command, if one exists*/ if (transfer_length) {
pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
us->recv_bulk_pipe : us->send_bulk_pipe;
result = usb_stor_bulk_srb(us, pipe, srb);
usb_stor_dbg(us, "CBI data stage result is 0x%x\n", result);
/* if we stalled the data transfer it means command failed */ if (result == USB_STOR_XFER_STALLED) return USB_STOR_TRANSPORT_FAILED; if (result > USB_STOR_XFER_STALLED) return USB_STOR_TRANSPORT_ERROR;
}
/* STATUS STAGE */
/* * NOTE: CB does not have a status stage. Silly, I know. So * we have to catch this at a higher level.
*/ if (us->protocol != USB_PR_CBI) return USB_STOR_TRANSPORT_GOOD;
result = usb_stor_intr_transfer(us, us->iobuf, 2);
usb_stor_dbg(us, "Got interrupt data (0x%x, 0x%x)\n",
us->iobuf[0], us->iobuf[1]); if (result != USB_STOR_XFER_GOOD) return USB_STOR_TRANSPORT_ERROR;
/* * UFI gives us ASC and ASCQ, like a request sense * * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI * devices, so we ignore the information for those commands. Note * that this means we could be ignoring a real error on these * commands, but that can't be helped.
*/ if (us->subclass == USB_SC_UFI) { if (srb->cmnd[0] == REQUEST_SENSE ||
srb->cmnd[0] == INQUIRY) return USB_STOR_TRANSPORT_GOOD; if (us->iobuf[0]) goto Failed; return USB_STOR_TRANSPORT_GOOD;
}
/* * If not UFI, we interpret the data as a result code * The first byte should always be a 0x0. * * Some bogus devices don't follow that rule. They stuff the ASC * into the first byte -- so if it's non-zero, call it a failure.
*/ if (us->iobuf[0]) {
usb_stor_dbg(us, "CBI IRQ data showed reserved bType 0x%x\n",
us->iobuf[0]); goto Failed;
}
/* The second byte & 0x0F should be 0x0 for good, otherwise error */ switch (us->iobuf[1] & 0x0F) { case 0x00: return USB_STOR_TRANSPORT_GOOD; case 0x01: goto Failed;
} return USB_STOR_TRANSPORT_ERROR;
/* * the CBI spec requires that the bulk pipe must be cleared * following any data-in/out command failure (section 2.4.3.1.3)
*/
Failed: if (pipe)
usb_stor_clear_halt(us, pipe); return USB_STOR_TRANSPORT_FAILED;
}
EXPORT_SYMBOL_GPL(usb_stor_CB_transport);
/* * Bulk only transport
*/
/* Determine what the maximum LUN supported is */ int usb_stor_Bulk_max_lun(struct us_data *us)
{ int result;
usb_stor_dbg(us, "GetMaxLUN command result is %d, data is %d\n",
result, us->iobuf[0]);
/* If we have a successful request, return the result if valid. */ if (result > 0) { if (us->iobuf[0] <= US_BULK_MAX_LUN_LIMIT) { return us->iobuf[0];
} else {
dev_info(&us->pusb_intf->dev, "Max LUN %d is not valid, using 0 instead",
us->iobuf[0]);
}
}
/* * Some devices don't like GetMaxLUN. They may STALL the control * pipe, they may return a zero-length result, they may do nothing at * all and timeout, or they may fail in even more bizarrely creative * ways. In these cases the best approach is to use the default * value: only one LUN.
*/ return 0;
}
/* send it to out endpoint */
usb_stor_dbg(us, "Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
le32_to_cpu(bcb->Signature), bcb->Tag,
le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
(bcb->Lun >> 4), (bcb->Lun & 0x0F),
bcb->Length);
result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
bcb, cbwlen, NULL);
usb_stor_dbg(us, "Bulk command transfer result=%d\n", result); if (result != USB_STOR_XFER_GOOD) return USB_STOR_TRANSPORT_ERROR;
/* DATA STAGE */ /* send/receive data payload, if there is any */
/* * Some USB-IDE converter chips need a 100us delay between the * command phase and the data phase. Some devices need a little * more than that, probably because of clock rate inaccuracies.
*/ if (unlikely(us->fflags & US_FL_GO_SLOW))
usleep_range(125, 150);
if (transfer_length) { unsignedint pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
us->recv_bulk_pipe : us->send_bulk_pipe;
result = usb_stor_bulk_srb(us, pipe, srb);
usb_stor_dbg(us, "Bulk data transfer result 0x%x\n", result); if (result == USB_STOR_XFER_ERROR) return USB_STOR_TRANSPORT_ERROR;
/* * If the device tried to send back more data than the * amount requested, the spec requires us to transfer * the CSW anyway. Since there's no point retrying * the command, we'll return fake sense data indicating * Illegal Request, Invalid Field in CDB.
*/ if (result == USB_STOR_XFER_LONG)
fake_sense = 1;
/* * Sometimes a device will mistakenly skip the data phase * and go directly to the status phase without sending a * zero-length packet. If we get a 13-byte response here, * check whether it really is a CSW.
*/ if (result == USB_STOR_XFER_SHORT &&
srb->sc_data_direction == DMA_FROM_DEVICE &&
transfer_length - scsi_get_resid(srb) ==
US_BULK_CS_WRAP_LEN) { struct scatterlist *sg = NULL; unsignedint offset = 0;
/* * See flow chart on pg 15 of the Bulk Only Transport spec for * an explanation of how this code works.
*/
/* get CSW for device status */
usb_stor_dbg(us, "Attempting to get CSW...\n");
result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
bcs, US_BULK_CS_WRAP_LEN, &cswlen);
/* * Some broken devices add unnecessary zero-length packets to the * end of their data transfers. Such packets show up as 0-length * CSWs. If we encounter such a thing, try to read the CSW again.
*/ if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
usb_stor_dbg(us, "Received 0-length CSW; retrying...\n");
result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
bcs, US_BULK_CS_WRAP_LEN, &cswlen);
}
/* did the attempt to read the CSW fail? */ if (result == USB_STOR_XFER_STALLED) {
/* get the status again */
usb_stor_dbg(us, "Attempting to get CSW (2nd try)...\n");
result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
bcs, US_BULK_CS_WRAP_LEN, NULL);
}
/* if we still have a failure at this point, we're in trouble */
usb_stor_dbg(us, "Bulk status result = %d\n", result); if (result != USB_STOR_XFER_GOOD) return USB_STOR_TRANSPORT_ERROR;
skipped_data_phase: /* check bulk status */
residue = le32_to_cpu(bcs->Residue);
usb_stor_dbg(us, "Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
le32_to_cpu(bcs->Signature), bcs->Tag,
residue, bcs->Status); if (!(bcs->Tag == us->tag || (us->fflags & US_FL_BULK_IGNORE_TAG)) ||
bcs->Status > US_BULK_STAT_PHASE) {
usb_stor_dbg(us, "Bulk logical error\n"); return USB_STOR_TRANSPORT_ERROR;
}
/* * Some broken devices report odd signatures, so we do not check them * for validity against the spec. We store the first one we see, * and check subsequent transfers for validity against this signature.
*/ if (!us->bcs_signature) {
us->bcs_signature = bcs->Signature; if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
usb_stor_dbg(us, "Learnt BCS signature 0x%08X\n",
le32_to_cpu(us->bcs_signature));
} elseif (bcs->Signature != us->bcs_signature) {
usb_stor_dbg(us, "Signature mismatch: got %08X, expecting %08X\n",
le32_to_cpu(bcs->Signature),
le32_to_cpu(us->bcs_signature)); return USB_STOR_TRANSPORT_ERROR;
}
/* * try to compute the actual residue, based on how much data * was really transferred and what the device tells us
*/ if (residue && !(us->fflags & US_FL_IGNORE_RESIDUE)) {
/* * Heuristically detect devices that generate bogus residues * by seeing what happens with INQUIRY and READ CAPACITY * commands.
*/ if (bcs->Status == US_BULK_STAT_OK &&
scsi_get_resid(srb) == 0 &&
((srb->cmnd[0] == INQUIRY &&
transfer_length == 36) ||
(srb->cmnd[0] == READ_CAPACITY &&
transfer_length == 8))) {
us->fflags |= US_FL_IGNORE_RESIDUE;
/* based on the status code, we report good or bad */ switch (bcs->Status) { case US_BULK_STAT_OK: /* device babbled -- return fake sense data */ if (fake_sense) {
memcpy(srb->sense_buffer,
usb_stor_sense_invalidCDB, sizeof(usb_stor_sense_invalidCDB)); return USB_STOR_TRANSPORT_NO_SENSE;
}
/* command good -- note that data could be short */ return USB_STOR_TRANSPORT_GOOD;
case US_BULK_STAT_FAIL: /* command failed */ return USB_STOR_TRANSPORT_FAILED;
case US_BULK_STAT_PHASE: /* * phase error -- note that a transport reset will be * invoked by the invoke_transport() function
*/ return USB_STOR_TRANSPORT_ERROR;
}
/* we should never get here, but if we do, we're in trouble */ return USB_STOR_TRANSPORT_ERROR;
}
EXPORT_SYMBOL_GPL(usb_stor_Bulk_transport);
/* * This is the common part of the device reset code. * * It's handy that every transport mechanism uses the control endpoint for * resets. * * Basically, we send a reset with a 5-second timeout, so we don't get * jammed attempting to do the reset.
*/ staticint usb_stor_reset_common(struct us_data *us,
u8 request, u8 requesttype,
u16 value, u16 index, void *data, u16 size)
{ int result; int result2;
if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
usb_stor_dbg(us, "No reset during disconnect\n"); return -EIO;
}
/* * Give the device some time to recover from the reset, * but don't delay disconnect processing.
*/
wait_event_interruptible_timeout(us->delay_wait,
test_bit(US_FLIDX_DISCONNECTING, &us->dflags),
HZ*6); if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
usb_stor_dbg(us, "Reset interrupted by disconnect\n"); return -EIO;
}
/* return a result code based on the result of the clear-halts */ if (result >= 0)
result = result2; if (result < 0)
usb_stor_dbg(us, "Soft reset failed\n"); else
usb_stor_dbg(us, "Soft reset done\n"); return result;
}
/* This issues a CB[I] Reset to the device in question */ #define CB_RESET_CMD_SIZE 12
/* * This issues a Bulk-only Reset to the device in question, including * clearing the subsequent endpoint halts that may occur.
*/ int usb_stor_Bulk_reset(struct us_data *us)
{ return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, us->ifnum, NULL, 0);
}
EXPORT_SYMBOL_GPL(usb_stor_Bulk_reset);
/* * Issue a USB port reset to the device. The caller must not hold * us->dev_mutex.
*/ int usb_stor_port_reset(struct us_data *us)
{ int result;
/*for these devices we must use the class specific method */ if (us->pusb_dev->quirks & USB_QUIRK_RESET) return -EPERM;
result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); if (result < 0)
usb_stor_dbg(us, "unable to lock device for reset: %d\n",
result); else { /* Were we disconnected while waiting for the lock? */ if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
result = -EIO;
usb_stor_dbg(us, "No reset during disconnect\n");
} else {
result = usb_reset_device(us->pusb_dev);
usb_stor_dbg(us, "usb_reset_device returns %d\n",
result);
}
usb_unlock_device(us->pusb_dev);
} return result;
}
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.
