[24/90] USB: usb-storage: add BAD_SENSE flag

[Greg KH]

2.6.31-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

commit a0bb108112a872c0b0c4b3ef4974f95fb75b155d upstream.

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@xxxxxxxxxxxxxxxxxxx>
Tested-by: Daniel Kukula <daniel.kuku@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 Documentation/kernel-parameters.txt |    2 ++
 drivers/usb/storage/transport.c     |   17 +++++++++++++----
 drivers/usb/storage/unusual_devs.h  |    7 +++++++
 drivers/usb/storage/usb.c           |    3 +++
 include/linux/usb_usual.h           |    4 +++-
 5 files changed, 28 insertions(+), 5 deletions(-)

--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2561,6 +2561,8 @@ and is between 256 and 4096 characters. 
 			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
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -666,10 +666,11 @@ void usb_stor_invoke_transport(struct sc
 	 * 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;
--- a/drivers/usb/storage/unusual_devs.h
+++ b/drivers/usb/storage/unusual_devs.h
@@ -838,6 +838,13 @@ UNUSUAL_DEV( 0x066f, 0x8000, 0x0001, 0x0
 		US_SC_DEVICE, US_PR_DEVICE, NULL,
 		US_FL_FIX_CAPACITY ),
 
+/* Reported by Daniel Kukula <daniel.kuku@xxxxxxxxx> */
+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@xxxxxxxxxx> */
 UNUSUAL_DEV( 0x067b, 0x2317, 0x0001, 0x001,
 		"Prolific Technology, Inc.",
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -460,6 +460,9 @@ static void adjust_quirks(struct us_data
 		case 'a':
 			f |= US_FL_SANE_SENSE;
 			break;
+		case 'b':
+			f |= US_FL_BAD_SENSE;
+			break;
 		case 'c':
 			f |= US_FL_FIX_CAPACITY;
 			break;
--- a/include/linux/usb_usual.h
+++ b/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 };


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