USB: usb-storage: add BAD_SENSE flag

This patch (as1311) fixes a problem in usb-storage: Some devices are
pretty broken when it comes to reporting sense data.  The information
they send back indicates that they have more than 18 bytes of sense
data available, but when the system asks for more than 18 they fail or
hang.  The symptom is that probing fails with multiple resets.

The patch adds a new BAD_SENSE flag to indicate that usb-storage
should never ask for more than 18 bytes of sense data.  The flag can
be set in an unusual_devs entry or via the "quirks=" module parameter,
and it is set automatically whenever a REQUEST SENSE command for more
than 18 bytes fails or times out.

An unusual_devs entry is added for the Agfa photo frame, which uses a
Prolific chip having this bug.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Daniel Kukula <daniel.kuku@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 4 deletions

diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index 589f6b4404f0..cc313d16d727 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -666,10 +666,11 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 	 * to wait for at least one CHECK_CONDITION to determine
 	 * SANE_SENSE support
 	 */
-	if ((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
+	if (unlikely((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
 	    result == USB_STOR_TRANSPORT_GOOD &&
 	    !(us->fflags & US_FL_SANE_SENSE) &&
-	    !(srb->cmnd[2] & 0x20)) {
+	    !(us->fflags & US_FL_BAD_SENSE) &&
+	    !(srb->cmnd[2] & 0x20))) {
 		US_DEBUGP("-- SAT supported, increasing auto-sense\n");
 		us->fflags |= US_FL_SANE_SENSE;
 	}
@@ -718,6 +719,12 @@ Retry_Sense:
 		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
 			US_DEBUGP("-- auto-sense aborted\n");
 			srb->result = DID_ABORT << 16;
+
+			/* 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;
 		}
 
@@ -727,10 +734,11 @@ Retry_Sense:
 		 * (small) sense request. This fixes some USB GSM modems
 		 */
 		if (temp_result == USB_STOR_TRANSPORT_FAILED &&
-		    (us->fflags & US_FL_SANE_SENSE) &&
-		    sense_size != US_SENSE_SIZE) {
+				sense_size != US_SENSE_SIZE) {
 			US_DEBUGP("-- 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;
 		}
 
@@ -754,6 +762,7 @@ Retry_Sense:
 		 */
 		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) {
 			US_DEBUGP("-- SANE_SENSE support enabled\n");
 			us->fflags |= US_FL_SANE_SENSE;