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linux-next/drivers/usb/storage/transport.c
Alan Stern b375a0495f [PATCH] USB: URB_ASYNC_UNLINK flag removed from the kernel
29 July 2005, Cambridge, MA:

This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK
flag from the Linux kernel.  Mr. Stern explained, "This flag is a relic
from an earlier, less-well-designed system.  For over a year it hasn't
been used for anything other than printing warning messages."

An anonymous spokesman for the Linux kernel development community
commented, "This is exactly the sort of thing we see happening all the
time.  As the kernel evolves, support for old techniques and old code can
be jettisoned and replaced by newer, better approaches.  Proprietary
operating systems do not have the freedom or flexibility to change so
quickly."

Mr. Stern, a staff member at Harvard University's Rowland Institute who
works on Linux only as a hobby, noted that the patch (labelled as548) did
not update two files, keyspan.c and option.c, in the USB drivers' "serial"
subdirectory.  "Those files need more extensive changes," he remarked.
"They examine the status field of several URBs at times when they're not
supposed to.  That will need to be fixed before the URB_ASYNC_UNLINK flag
is removed."

Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all
of Linux's USB drivers, did not respond to our inquiries or return our
calls.  His only comment was "Applied, thanks."

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-08 16:23:04 -07:00

1243 lines
38 KiB
C

/* Driver for USB Mass Storage compliant devices
*
* $Id: transport.c,v 1.47 2002/04/22 03:39:43 mdharm Exp $
*
* 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/config.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.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->flags 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->flags
* 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->flags 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 pt_regs *regs)
{
struct completion *urb_done_ptr = (struct completion *)urb->context;
complete(urb_done_ptr);
}
/* This is the timeout handler which will cancel an URB when its timeout
* expires.
*/
static void timeout_handler(unsigned long us_)
{
struct us_data *us = (struct us_data *) us_;
if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) {
US_DEBUGP("Timeout -- cancelling URB\n");
usb_unlink_urb(us->current_urb);
}
}
/* 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;
struct timer_list to_timer;
int status;
/* don't submit URBs during abort/disconnect processing */
if (us->flags & ABORTING_OR_DISCONNECTING)
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->flags);
/* did an abort/disconnect occur during the submission? */
if (us->flags & ABORTING_OR_DISCONNECTING) {
/* cancel the URB, if it hasn't been cancelled already */
if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) {
US_DEBUGP("-- cancelling URB\n");
usb_unlink_urb(us->current_urb);
}
}
/* submit the timeout timer, if a timeout was requested */
if (timeout > 0) {
init_timer(&to_timer);
to_timer.expires = jiffies + timeout;
to_timer.function = timeout_handler;
to_timer.data = (unsigned long) us;
add_timer(&to_timer);
}
/* wait for the completion of the URB */
wait_for_completion(&urb_done);
clear_bit(US_FLIDX_URB_ACTIVE, &us->flags);
/* clean up the timeout timer */
if (timeout > 0)
del_timer_sync(&to_timer);
/* 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",
__FUNCTION__, 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", __FUNCTION__, 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;
/* timeout or excessively long NAK */
case -ETIMEDOUT:
US_DEBUGP("-- timeout or NAK\n");
return USB_STOR_XFER_ERROR;
/* 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",
__FUNCTION__, 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", __FUNCTION__, 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", __FUNCTION__, 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/disconnect processing */
if (us->flags & ABORTING_OR_DISCONNECTING)
return USB_STOR_XFER_ERROR;
/* initialize the scatter-gather request block */
US_DEBUGP("%s: xfer %u bytes, %d entries\n", __FUNCTION__,
length, num_sg);
result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
sg, num_sg, length, SLAB_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->flags);
/* did an abort/disconnect occur during the submission? */
if (us->flags & ABORTING_OR_DISCONNECTING) {
/* cancel the request, if it hasn't been cancelled already */
if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) {
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->flags);
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);
}
/*
* 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 */
srb->resid = 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->flags)) {
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 ((srb->resid > 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;
void* old_request_buffer;
unsigned short old_sg;
unsigned old_request_bufflen;
unsigned char old_sc_data_direction;
unsigned char old_cmd_len;
unsigned char old_cmnd[MAX_COMMAND_SIZE];
int old_resid;
US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
/* save the old command */
memcpy(old_cmnd, srb->cmnd, MAX_COMMAND_SIZE);
old_cmd_len = srb->cmd_len;
/* set the command and the LUN */
memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
srb->cmnd[0] = REQUEST_SENSE;
srb->cmnd[1] = old_cmnd[1] & 0xE0;
srb->cmnd[4] = 18;
/* FIXME: we must do the protocol translation here */
if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI)
srb->cmd_len = 6;
else
srb->cmd_len = 12;
/* set the transfer direction */
old_sc_data_direction = srb->sc_data_direction;
srb->sc_data_direction = DMA_FROM_DEVICE;
/* use the new buffer we have */
old_request_buffer = srb->request_buffer;
srb->request_buffer = srb->sense_buffer;
/* set the buffer length for transfer */
old_request_bufflen = srb->request_bufflen;
srb->request_bufflen = 18;
/* set up for no scatter-gather use */
old_sg = srb->use_sg;
srb->use_sg = 0;
/* issue the auto-sense command */
old_resid = srb->resid;
srb->resid = 0;
temp_result = us->transport(us->srb, us);
/* let's clean up right away */
srb->resid = old_resid;
srb->request_buffer = old_request_buffer;
srb->request_bufflen = old_request_bufflen;
srb->use_sg = old_sg;
srb->sc_data_direction = old_sc_data_direction;
srb->cmd_len = old_cmd_len;
memcpy(srb->cmnd, old_cmnd, MAX_COMMAND_SIZE);
if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
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->flags & 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->request_bufflen - srb->resid < 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:
/* Let the SCSI layer know we are doing a reset, set the
* RESETTING bit, and clear the ABORTING bit so that the reset
* may proceed. */
scsi_lock(us_to_host(us));
usb_stor_report_bus_reset(us);
set_bit(US_FLIDX_RESETTING, &us->flags);
clear_bit(US_FLIDX_ABORTING, &us->flags);
scsi_unlock(us_to_host(us));
result = usb_stor_port_reset(us);
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->flags);
}
/* Stop the current URB transfer */
void usb_stor_stop_transport(struct us_data *us)
{
US_DEBUGP("%s called\n", __FUNCTION__);
/* 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->flags)) {
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->flags)) {
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 = srb->request_bufflen;
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_transfer_sg(us, pipe,
srb->request_buffer, transfer_length,
srb->use_sg, &srb->resid);
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 = srb->request_bufflen;
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_transfer_sg(us, pipe,
srb->request_buffer, transfer_length,
srb->use_sg, &srb->resid);
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 */
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 (i.e. Iomega Zip100) need this -- apparently
* the bulk pipes get STALLed when the GetMaxLUN request is
* processed. This is, in theory, harmless to all other devices
* (regardless of if they stall or not).
*/
if (result == -EPIPE) {
usb_stor_clear_halt(us, us->recv_bulk_pipe);
usb_stor_clear_halt(us, us->send_bulk_pipe);
}
/*
* 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 = srb->request_bufflen;
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->flags & 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->flags & 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->flags & 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_transfer_sg(us, pipe,
srb->request_buffer, transfer_length,
srb->use_sg, &srb->resid);
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 || 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) {
if (!(us->flags & US_FL_IGNORE_RESIDUE)) {
residue = min(residue, transfer_length);
srb->resid = max(srb->resid, (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->flags)) {
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->flags),
HZ*6);
if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
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", __FUNCTION__);
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", __FUNCTION__);
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. But don't do anything if
* there's more than one interface in the device, so that other users
* are not affected. */
int usb_stor_port_reset(struct us_data *us)
{
int result, rc;
if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
result = -EIO;
US_DEBUGP("No reset during disconnect\n");
} else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) {
result = -EBUSY;
US_DEBUGP("Refusing to reset a multi-interface device\n");
} else {
result = rc =
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 {
result = usb_reset_device(us->pusb_dev);
if (rc)
usb_unlock_device(us->pusb_dev);
US_DEBUGP("usb_reset_device returns %d\n", result);
}
}
return result;
}