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>

Documentation/kernel-parameters.txt

@@ -2663,6 +2663,8 @@ and is between 256 and 4096 characters. It is defined in the file
 			to a common usb-storage quirk flag as follows:
 				a = SANE_SENSE (collect more than 18 bytes
 					of sense data);
+				b = BAD_SENSE (don't collect more than 18
+					bytes of sense data);
 				c = FIX_CAPACITY (decrease the reported
 					device capacity by one sector);
 				h = CAPACITY_HEURISTICS (decrease the

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 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 		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 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 		 * (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 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 		 */
 		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;

drivers/usb/storage/unusual_devs.h

@@ -818,6 +818,13 @@ UNUSUAL_DEV( 0x066f, 0x8000, 0x0001, 0x0001,
 		US_SC_DEVICE, US_PR_DEVICE, NULL,
 		US_FL_FIX_CAPACITY ),
 
+/* Reported by Daniel Kukula <daniel.kuku@gmail.com> */
+UNUSUAL_DEV( 0x067b, 0x1063, 0x0100, 0x0100,
+		"Prolific Technology, Inc.",
+		"Prolific Storage Gadget",
+		US_SC_DEVICE, US_PR_DEVICE, NULL,
+		US_FL_BAD_SENSE ),
+
 /* Reported by Rogerio Brito <rbrito@ime.usp.br> */
 UNUSUAL_DEV( 0x067b, 0x2317, 0x0001, 0x001,
 		"Prolific Technology, Inc.",

drivers/usb/storage/usb.c

@@ -463,6 +463,9 @@ static void adjust_quirks(struct us_data *us)
 		case 'a':
 			f |= US_FL_SANE_SENSE;
 			break;
+		case 'b':
+			f |= US_FL_BAD_SENSE;
+			break;
 		case 'c':
 			f |= US_FL_FIX_CAPACITY;
 			break;

include/linux/usb_usual.h

@@ -56,7 +56,9 @@
 	US_FLAG(SANE_SENSE,     0x00008000)			\
 		/* Sane Sense (> 18 bytes) */			\
 	US_FLAG(CAPACITY_OK,	0x00010000)			\
-		/* READ CAPACITY response is correct */
+		/* READ CAPACITY response is correct */		\
+	US_FLAG(BAD_SENSE,	0x00020000)			\
+		/* Bad Sense (never more than 18 bytes) */
 
 #define US_FLAG(name, value)	US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };