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 <st...@rowland.harvard.edu>
Reported-by: Michael Büsch <m...@bues.ch>
Tested-by: Michael Büsch <m...@bues.ch>
Acked-by: James Bottomley <james.bottom...@hansenpartnership.com>
CC: Matthew Dharm <mdharm-...@one-eyed-alien.net>
CC: <sta...@vger.kernel.org>

---


[as1751]


 drivers/scsi/sd.c                  |    5 ++++-
 drivers/usb/storage/scsiglue.c     |    4 ++++
 drivers/usb/storage/unusual_devs.h |    7 +++++++
 include/linux/usb_usual.h          |    4 +++-
 include/scsi/scsi_device.h         |    1 +
 5 files changed, 19 insertions(+), 2 deletions(-)

Index: usb-3.16/include/linux/usb_usual.h
===================================================================
--- usb-3.16.orig/include/linux/usb_usual.h
+++ usb-3.16/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 };
Index: usb-3.16/include/scsi/scsi_device.h
===================================================================
--- usb-3.16.orig/include/scsi/scsi_device.h
+++ usb-3.16/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 */
 
Index: usb-3.16/drivers/usb/storage/unusual_devs.h
===================================================================
--- usb-3.16.orig/drivers/usb/storage/unusual_devs.h
+++ usb-3.16/drivers/usb/storage/unusual_devs.h
@@ -1936,6 +1936,13 @@ UNUSUAL_DEV(  0x14cd, 0x6600, 0x0201, 0x
                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 <ol...@lsd.ic.unicamp.br>
  * JMicron responds to USN and several other SCSI ioctls with a
  * residue that causes subsequent I/O requests to fail.  */
Index: usb-3.16/drivers/usb/storage/scsiglue.c
===================================================================
--- usb-3.16.orig/drivers/usb/storage/scsiglue.c
+++ usb-3.16/drivers/usb/storage/scsiglue.c
@@ -256,6 +256,10 @@ static int slave_configure(struct scsi_d
                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
Index: usb-3.16/drivers/scsi/sd.c
===================================================================
--- usb-3.16.orig/drivers/scsi/sd.c
+++ usb-3.16/drivers/scsi/sd.c
@@ -2441,7 +2441,10 @@ sd_read_cache_type(struct scsi_disk *sdk
                }
 
                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;


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