leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

USB: storage: When a device returns no sense data, call it a Hardware Error

Browse Source 
This patch (as1294) fixes a problem that has plagued users for several
kernel releases.  Some USB mass-storage devices don't return any sense
data when they encounter certain kinds of errors.  The SCSI layer
interprets this to mean that the operation should be retried, and the
same thing happens -- over and over again with no limit.  In some
circumstances (such as when a bus reset occurs) that is the right
thing to do, but not here.

The patch checks for this condition (a transport failure with no sense
data) and changes the result code to DID_ERROR and the sense code to
Hardware Error.  This does get only a limited number of retries, and
so the command will fail relatively quickly instead of getting stuck
in an infinite loop.

This fixes a large part of Bugzilla #14118.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Mantas Mikulenas <grawity@gmail.com>
CC: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2009-10-06 14:07:57 -04:00 committed by Greg Kroah-Hartman
parent a5f6005d7b
commit f1a0743bc0
1 changed files with 22 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
drivers/usb/storage/transport.c
View File

@ -768,17 +768,32 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
/* 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 */
/* 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 ( /* 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;
/* 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;
/* 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;
srb->sense_buffer[2] = HARDWARE_ERROR;
}
}
}