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linux/drivers/usb/storage/transport.c

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/* 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.
*
* Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
* information about this driver.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_device.h>
#include "usb.h"
#include "transport.h"
#include "protocol.h"
#include "scsiglue.h"
#include "debug.h"
/***********************************************************************
* 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.
*/
static void 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.
*/
static int 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->actual_length = 0;
us->current_urb->error_count = 0;
us->current_urb->status = 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. */
us->current_urb->transfer_flags = URB_NO_SETUP_DMA_MAP;
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;
us->current_urb->setup_dma = us->cr_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)) {
US_DEBUGP("-- 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);
clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
if (timeleft <= 0) {
US_DEBUGP("%s -- cancelling URB\n",
timeleft == 0 ? "Timeout" : "Signal");
usb_kill_urb(us->current_urb);
}
/* 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, unsigned int pipe,
u8 request, u8 requesttype, u16 value, u16 index,
void *data, u16 size, int timeout)
{
int status;
US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
__func__, request, requesttype,
value, index, size);
/* 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,
(unsigned char*) 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;
}
/* 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, unsigned int pipe)
{
int result;
int endp = usb_pipeendpoint(pipe);
if (usb_pipein (pipe))
endp |= USB_DIR_IN;
result = usb_stor_control_msg(us, us->send_ctrl_pipe,
USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
USB_ENDPOINT_HALT, endp,
NULL, 0, 3*HZ);
/* reset the endpoint toggle */
if (result >= 0)
usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe),
usb_pipeout(pipe), 0);
US_DEBUGP("%s: result = %d\n", __func__, result);
return result;
}
/*
* 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.
*/
static int interpret_urb_result(struct us_data *us, unsigned int pipe,
unsigned int length, int result, unsigned int partial)
{
US_DEBUGP("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) {
US_DEBUGP("-- short transfer\n");
return USB_STOR_XFER_SHORT;
}
US_DEBUGP("-- 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)) {
US_DEBUGP("-- stall on control pipe\n");
return USB_STOR_XFER_STALLED;
}
/* for other sorts of endpoint, clear the stall */
US_DEBUGP("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:
US_DEBUGP("-- babble\n");
return USB_STOR_XFER_LONG;
/* the transfer was cancelled by abort, disconnect, or timeout */
case -ECONNRESET:
US_DEBUGP("-- transfer cancelled\n");
return USB_STOR_XFER_ERROR;
/* short scatter-gather read transfer */
case -EREMOTEIO:
US_DEBUGP("-- short read transfer\n");
return USB_STOR_XFER_SHORT;
/* abort or disconnect in progress */
case -EIO:
US_DEBUGP("-- abort or disconnect in progress\n");
return USB_STOR_XFER_ERROR;
/* the catch-all error case */
default:
US_DEBUGP("-- 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, unsigned int pipe,
u8 request, u8 requesttype, u16 value, u16 index,
void *data, u16 size)
{
int result;
US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
__func__, request, requesttype,
value, index, size);
/* 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,
(unsigned char*) us->cr, data, size,
usb_stor_blocking_completion, NULL);
result = usb_stor_msg_common(us, 0);
return interpret_urb_result(us, pipe, size, result,
us->current_urb->actual_length);
}
/*
* 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.
*/
static int usb_stor_intr_transfer(struct us_data *us, void *buf,
unsigned int length)
{
int result;
unsigned int pipe = us->recv_intr_pipe;
unsigned int maxp;
US_DEBUGP("%s: xfer %u bytes\n", __func__, length);
/* calculate the max packet size */
maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(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);
return interpret_urb_result(us, pipe, length, result,
us->current_urb->actual_length);
}
/*
* 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, unsigned int pipe,
void *buf, unsigned int length, unsigned int *act_len)
{
int result;
US_DEBUGP("%s: xfer %u bytes\n", __func__, 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);
}
/*
* 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.
*/
static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
struct scatterlist *sg, int num_sg, unsigned int length,
unsigned int *act_len)
{
int result;
/* don't submit s-g requests during abort processing */
if (test_bit(US_FLIDX_ABORTING, &us->dflags))
return USB_STOR_XFER_ERROR;
/* initialize the scatter-gather request block */
US_DEBUGP("%s: xfer %u bytes, %d entries\n", __func__,
length, num_sg);
result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
sg, num_sg, length, GFP_NOIO);
if (result) {
US_DEBUGP("usb_sg_init returned %d\n", result);
return 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)) {
US_DEBUGP("-- 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);
}
/*
* 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, unsigned int pipe,
struct scsi_cmnd* srb)
{
unsigned int partial;
int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
scsi_sg_count(srb), scsi_bufflen(srb),
&partial);
scsi_set_resid(srb, scsi_bufflen(srb) - partial);
return result;
}
/*
* 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, unsigned int pipe,
void *buf, unsigned int length_left, int use_sg, int *residual)
{
int result;
unsigned int 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;
}
/***********************************************************************
* Transport routines
***********************************************************************/
/* 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)) {
US_DEBUGP("-- 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) {
US_DEBUGP("-- 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;
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 == US_PR_CB || us->protocol == US_PR_DPCM_USB) &&
srb->sc_data_direction != DMA_FROM_DEVICE) {
US_DEBUGP("-- CB transport device requiring auto-sense\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) {
US_DEBUGP("-- transport indicates command failure\n");
need_auto_sense = 1;
}
/*
* 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))) {
US_DEBUGP("-- 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;
US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
scsi_eh_prep_cmnd(srb, &ses, NULL, 0, US_SENSE_SIZE);
/* FIXME: we must do the protocol translation here */
if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI ||
us->subclass == US_SC_CYP_ATACB)
srb->cmd_len = 6;
else
srb->cmd_len = 12;
/* issue the auto-sense command */
scsi_set_resid(srb, 0);
temp_result = us->transport(us->srb, us);
/* let's clean up right away */
scsi_eh_restore_cmnd(srb, &ses);
if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
US_DEBUGP("-- auto-sense aborted\n");
srb->result = DID_ABORT << 16;
goto Handle_Errors;
}
if (temp_result != USB_STOR_TRANSPORT_GOOD) {
US_DEBUGP("-- 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;
}
US_DEBUGP("-- Result from auto-sense is %d\n", temp_result);
US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
srb->sense_buffer[0],
srb->sense_buffer[2] & 0xf,
srb->sense_buffer[12],
srb->sense_buffer[13]);
#ifdef CONFIG_USB_STORAGE_DEBUG
usb_stor_show_sense(
srb->sense_buffer[2] & 0xf,
srb->sense_buffer[12],
srb->sense_buffer[13]);
#endif
/* set the result so the higher layers expect this data */
srb->result = SAM_STAT_CHECK_CONDITION;
/* 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 &&
/* Filemark 0, ignore EOM, ILI 0, no sense */
(srb->sense_buffer[2] & 0xaf) == 0 &&
/* No ASC or ASCQ */
srb->sense_buffer[12] == 0 &&
srb->sense_buffer[13] == 0) {
srb->result = SAM_STAT_GOOD;
srb->sense_buffer[0] = 0x0;
}
}
/* 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) | (SUGGEST_RETRY << 24);
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);
if (result < 0) {
scsi_lock(us_to_host(us));
usb_stor_report_device_reset(us);
scsi_unlock(us_to_host(us));
us->transport_reset(us);
}
clear_bit(US_FLIDX_RESETTING, &us->dflags);
}
/* Stop the current URB transfer */
void usb_stor_stop_transport(struct us_data *us)
{
US_DEBUGP("%s called\n", __func__);
/* 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)) {
US_DEBUGP("-- 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)) {
US_DEBUGP("-- cancelling sg request\n");
usb_sg_cancel(&us->current_sg);
}
}
/*
* Control/Bulk/Interrupt transport
*/
int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us)
{
unsigned int transfer_length = scsi_bufflen(srb);
unsigned int pipe = 0;
int result;
/* COMMAND STAGE */
/* let's send the command via the control pipe */
result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
US_CBI_ADSC,
USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
us->ifnum, srb->cmnd, srb->cmd_len);
/* check the return code for the command */
US_DEBUGP("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);
US_DEBUGP("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 */
result = usb_stor_intr_transfer(us, us->iobuf, 2);
US_DEBUGP("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 == US_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]) {
US_DEBUGP("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;
}
/*
* Control/Bulk transport
*/
int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
{
unsigned int transfer_length = scsi_bufflen(srb);
int result;
/* COMMAND STAGE */
/* let's send the command via the control pipe */
result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
US_CBI_ADSC,
USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
us->ifnum, srb->cmnd, srb->cmd_len);
/* check the return code for the command */
US_DEBUGP("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) {
unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
us->recv_bulk_pipe : us->send_bulk_pipe;
result = usb_stor_bulk_srb(us, pipe, srb);
US_DEBUGP("CB 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.
*/
return USB_STOR_TRANSPORT_GOOD;
}
/*
* Bulk only transport
*/
/* Determine what the maximum LUN supported is */
int usb_stor_Bulk_max_lun(struct us_data *us)
{
int result;
/* issue the command */
us->iobuf[0] = 0;
result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
US_BULK_GET_MAX_LUN,
USB_DIR_IN | USB_TYPE_CLASS |
USB_RECIP_INTERFACE,
0, us->ifnum, us->iobuf, 1, HZ);
US_DEBUGP("GetMaxLUN command result is %d, data is %d\n",
result, us->iobuf[0]);
/* if we have a successful request, return the result */
if (result > 0)
return 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;
}
int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
{
struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
unsigned int transfer_length = scsi_bufflen(srb);
unsigned int residue;
int result;
int fake_sense = 0;
unsigned int cswlen;
unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
/* Take care of BULK32 devices; set extra byte to 0 */
if (unlikely(us->fflags & US_FL_BULK32)) {
cbwlen = 32;
us->iobuf[31] = 0;
}
/* set up the command wrapper */
bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
bcb->DataTransferLength = cpu_to_le32(transfer_length);
bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0;
bcb->Tag = ++us->tag;
bcb->Lun = srb->device->lun;
if (us->fflags & US_FL_SCM_MULT_TARG)
bcb->Lun |= srb->device->id << 4;
bcb->Length = srb->cmd_len;
/* copy the command payload */
memset(bcb->CDB, 0, sizeof(bcb->CDB));
memcpy(bcb->CDB, srb->cmnd, bcb->Length);
/* send it to out endpoint */
US_DEBUGP("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);
US_DEBUGP("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))
udelay(125);
if (transfer_length) {
unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
us->recv_bulk_pipe : us->send_bulk_pipe;
result = usb_stor_bulk_srb(us, pipe, srb);
US_DEBUGP("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
* the command, we'll return fake sense data indicating
* Illegal Request, Invalid Field in CDB.
*/
if (result == USB_STOR_XFER_LONG)
fake_sense = 1;
}
/* 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 */
US_DEBUGP("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) {
US_DEBUGP("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 */
US_DEBUGP("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 */
US_DEBUGP("Bulk status result = %d\n", result);
if (result != USB_STOR_XFER_GOOD)
return USB_STOR_TRANSPORT_ERROR;
/* check bulk status */
residue = le32_to_cpu(bcs->Residue);
US_DEBUGP("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) {
US_DEBUGP("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))
US_DEBUGP("Learnt BCS signature 0x%08X\n",
le32_to_cpu(us->bcs_signature));
} else if (bcs->Signature != us->bcs_signature) {
US_DEBUGP("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;
} else {
residue = min(residue, transfer_length);
scsi_set_resid(srb, max(scsi_get_resid(srb),
(int) 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;
}
/***********************************************************************
* Reset routines
***********************************************************************/
/* 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.
*/
static int 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)) {
US_DEBUGP("No reset during disconnect\n");
return -EIO;
}
result = usb_stor_control_msg(us, us->send_ctrl_pipe,
request, requesttype, value, index, data, size,
5*HZ);
if (result < 0) {
US_DEBUGP("Soft reset failed: %d\n", result);
return result;
}
/* 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)) {
US_DEBUGP("Reset interrupted by disconnect\n");
return -EIO;
}
US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n");
result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n");
result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
/* return a result code based on the result of the clear-halts */
if (result >= 0)
result = result2;
if (result < 0)
US_DEBUGP("Soft reset failed\n");
else
US_DEBUGP("Soft reset done\n");
return result;
}
/* This issues a CB[I] Reset to the device in question
*/
#define CB_RESET_CMD_SIZE 12
int usb_stor_CB_reset(struct us_data *us)
{
US_DEBUGP("%s called\n", __func__);
memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
us->iobuf[0] = SEND_DIAGNOSTIC;
us->iobuf[1] = 4;
return usb_stor_reset_common(us, US_CBI_ADSC,
USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
}
/* 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)
{
US_DEBUGP("%s called\n", __func__);
return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, us->ifnum, NULL, 0);
}
/* 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, rc_lock;
result = rc_lock =
usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
if (result < 0)
US_DEBUGP("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;
US_DEBUGP("No reset during disconnect\n");
} else {
result = usb_reset_device(us->pusb_dev);
US_DEBUGP("usb_reset_device returns %d\n",
result);
}
if (rc_lock)
usb_unlock_device(us->pusb_dev);
}
return result;
}
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