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[PATCH] USB Storage: port reset on transport error
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This patch causes a port reset whenever there's a transport error or abort.
If that fails it reverts back to doing a mass-storage device reset.  It
started life as as497 and was rediffed by me.

This makes error recovery a lot quicker and more reliable.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Matthew Dharm authored and Greg Kroah-Hartman committed Jun 27, 2005
1 parent 5203ad4 commit 4d07ef7
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Showing 4 changed files with 82 additions and 64 deletions.
45 changes: 13 additions & 32 deletions drivers/usb/storage/scsiglue.c
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Original file line number Diff line number Diff line change
Expand Up @@ -255,50 +255,23 @@ static int device_reset(struct scsi_cmnd *srb)

/* lock the device pointers and do the reset */
down(&(us->dev_semaphore));
if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
result = FAILED;
US_DEBUGP("No reset during disconnect\n");
} else
result = us->transport_reset(us);
result = us->transport_reset(us);
up(&(us->dev_semaphore));

return result;
return result < 0 ? FAILED : SUCCESS;
}

/* This resets the device's USB port. */
/* It refuses to work if there's more than one interface in
* the device, so that other users are not affected. */
/* Simulate a SCSI bus reset by resetting the device's USB port. */
/* This is always called with scsi_lock(host) held */
static int bus_reset(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
int result, rc;
int result;

US_DEBUGP("%s called\n", __FUNCTION__);

/* The USB subsystem doesn't handle synchronisation between
* a device's several drivers. Therefore we reset only devices
* with just one interface, which we of course own. */

down(&(us->dev_semaphore));
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 {
rc = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
if (rc < 0) {
US_DEBUGP("unable to lock device for reset: %d\n", rc);
result = rc;
} 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);
}
}
result = usb_stor_port_reset(us);
up(&(us->dev_semaphore));

/* lock the host for the return */
Expand All @@ -320,6 +293,14 @@ void usb_stor_report_device_reset(struct us_data *us)
}
}

/* Report a driver-initiated bus reset to the SCSI layer.
* Calling this for a SCSI-initiated reset is unnecessary but harmless.
* The caller must own the SCSI host lock. */
void usb_stor_report_bus_reset(struct us_data *us)
{
scsi_report_bus_reset(us_to_host(us), 0);
}

/***********************************************************************
* /proc/scsi/ functions
***********************************************************************/
Expand Down
1 change: 1 addition & 0 deletions drivers/usb/storage/scsiglue.h
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Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,7 @@
#define _SCSIGLUE_H_

extern void usb_stor_report_device_reset(struct us_data *us);
extern void usb_stor_report_bus_reset(struct us_data *us);

extern unsigned char usb_stor_sense_invalidCDB[18];
extern struct scsi_host_template usb_stor_host_template;
Expand Down
99 changes: 67 additions & 32 deletions drivers/usb/storage/transport.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -541,15 +541,15 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
*/
if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
US_DEBUGP("-- command was aborted\n");
goto Handle_Abort;
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");
us->transport_reset(us);
srb->result = DID_ERROR << 16;
return;
goto Handle_Errors;
}

/* if the transport provided its own sense data, don't auto-sense */
Expand Down Expand Up @@ -669,7 +669,8 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)

if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
US_DEBUGP("-- auto-sense aborted\n");
goto Handle_Abort;
srb->result = DID_ABORT << 16;
goto Handle_Errors;
}
if (temp_result != USB_STOR_TRANSPORT_GOOD) {
US_DEBUGP("-- auto-sense failure\n");
Expand All @@ -678,9 +679,9 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
* multi-target device, since failure of an
* auto-sense is perfectly valid
*/
if (!(us->flags & US_FL_SCM_MULT_TARG))
us->transport_reset(us);
srb->result = DID_ERROR << 16;
if (!(us->flags & US_FL_SCM_MULT_TARG))
goto Handle_Errors;
return;
}

Expand Down Expand Up @@ -721,12 +722,28 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)

return;

/* abort processing: the bulk-only transport requires a reset
* following an abort */
Handle_Abort:
srb->result = DID_ABORT << 16;
if (us->protocol == US_PR_BULK)
/* 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 */
Expand Down Expand Up @@ -1134,24 +1151,18 @@ static int usb_stor_reset_common(struct us_data *us,
{
int result;
int result2;
int rc = FAILED;

/* 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_device_reset(us);
set_bit(US_FLIDX_RESETTING, &us->flags);
clear_bit(US_FLIDX_ABORTING, &us->flags);
scsi_unlock(us_to_host(us));
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);
goto Done;
return result;
}

/* Give the device some time to recover from the reset,
Expand All @@ -1161,7 +1172,7 @@ static int usb_stor_reset_common(struct us_data *us,
HZ*6);
if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
US_DEBUGP("Reset interrupted by disconnect\n");
goto Done;
return -EIO;
}

US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n");
Expand All @@ -1173,16 +1184,11 @@ static int usb_stor_reset_common(struct us_data *us,
/* return a result code based on the result of the clear-halts */
if (result >= 0)
result = result2;
if (result < 0) {
if (result < 0)
US_DEBUGP("Soft reset failed\n");
goto Done;
}
US_DEBUGP("Soft reset done\n");
rc = SUCCESS;

Done:
clear_bit(US_FLIDX_RESETTING, &us->flags);
return rc;
else
US_DEBUGP("Soft reset done\n");
return result;
}

/* This issues a CB[I] Reset to the device in question
Expand Down Expand Up @@ -1212,3 +1218,32 @@ int usb_stor_Bulk_reset(struct us_data *us)
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;
}
1 change: 1 addition & 0 deletions drivers/usb/storage/transport.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -171,4 +171,5 @@ extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
void *buf, unsigned int length, int use_sg, int *residual);

extern int usb_stor_port_reset(struct us_data *us);
#endif

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