usb-storage/SCSI: Add broken_fua blacklist flag

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs.  This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Michael Büsch <m@bues.ch>
Tested-by: Michael Büsch <m@bues.ch>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/scsi/sd.c

@@ -2441,7 +2441,10 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 		}
 
 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
-		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
+		if (sdp->broken_fua) {
+			sd_first_printk(KERN_NOTICE, sdkp, "Disabling FUA\n");
+			sdkp->DPOFUA = 0;
+		} else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
 			sd_first_printk(KERN_NOTICE, sdkp,
 				  "Uses READ/WRITE(6), disabling FUA\n");
 			sdkp->DPOFUA = 0;

drivers/usb/storage/scsiglue.c

@@ -256,6 +256,10 @@ static int slave_configure(struct scsi_device *sdev)
 		if (us->fflags & US_FL_WRITE_CACHE)
 			sdev->wce_default_on = 1;
 
+		/* A few buggy USB-ATA bridges don't understand FUA */
+		if (us->fflags & US_FL_BROKEN_FUA)
+			sdev->broken_fua = 1;
+
 	} else {
 
 		/* Non-disk-type devices don't need to blacklist any pages

drivers/usb/storage/unusual_devs.h

@@ -1936,6 +1936,13 @@ UNUSUAL_DEV(  0x14cd, 0x6600, 0x0201, 0x0201,
 		USB_SC_DEVICE, USB_PR_DEVICE, NULL,
 		US_FL_IGNORE_RESIDUE ),
 
+/* Reported by Michael Büsch <m@bues.ch> */
+UNUSUAL_DEV(  0x152d, 0x0567, 0x0114, 0x0114,
+		"JMicron",
+		"USB to ATA/ATAPI Bridge",
+		USB_SC_DEVICE, USB_PR_DEVICE, NULL,
+		US_FL_BROKEN_FUA ),
+
 /* Reported by Alexandre Oliva <oliva@lsd.ic.unicamp.br>
  * JMicron responds to USN and several other SCSI ioctls with a
  * residue that causes subsequent I/O requests to fail.  */

include/linux/usb_usual.h

@@ -70,7 +70,9 @@
 	US_FLAG(NEEDS_CAP16,	0x00400000)			\
 		/* cannot handle READ_CAPACITY_10 */		\
 	US_FLAG(IGNORE_UAS,	0x00800000)			\
-		/* Device advertises UAS but it is broken */
+		/* Device advertises UAS but it is broken */	\
+	US_FLAG(BROKEN_FUA,	0x01000000)			\
+		/* Cannot handle FUA in WRITE or READ CDBs */	\
 
 #define US_FLAG(name, value)	US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };

include/scsi/scsi_device.h

@@ -173,6 +173,7 @@ struct scsi_device {
 	unsigned is_visible:1;	/* is the device visible in sysfs */
 	unsigned wce_default_on:1;	/* Cache is ON by default */
 	unsigned no_dif:1;	/* T10 PI (DIF) should be disabled */
+	unsigned broken_fua:1;		/* Don't set FUA bit */
 
 	atomic_t disk_events_disable_depth; /* disable depth for disk events */