USB Storage: indistinguishable devices with broken and unbroken firmware

there's a USB mass storage device which exists in two version. One
reports the correct size and the other does not. Apart from that they
are identical and cannot be told apart. Here's a heuristic based on the
empirical finding that drives have even sizes.


Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 4 insertions, 1 deletions

diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 2ae76fe52ff7..1b792b9286ba 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -46,7 +46,9 @@
         US_FLAG(MAX_SECTORS_64, 0x00000400)                     \
                 /* Sets max_sectors to 64    */                 \
         US_FLAG(IGNORE_DEVICE,  0x00000800)                     \
-                /* Don't claim device */
+                /* Don't claim device */                        \
+        US_FLAG(CAPACITY_HEURISTICS,    0x00001000)             \
+                /* sometimes sizes is too big */
 
 #define US_FLAG(name, value)    US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index ebf31b16dc49..9dd37e2f5a84 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -122,6 +122,7 @@ struct scsi_device {
         unsigned no_uld_attach:1; /* disable connecting to upper level drivers */
         unsigned select_no_atn:1;
         unsigned fix_capacity:1;        /* READ_CAPACITY is too high by 1 */
+        unsigned guess_capacity:1;      /* READ_CAPACITY might be too high by 1 */
         unsigned retry_hwerror:1;       /* Retry HARDWARE_ERROR */
 
         unsigned int device_blocked;    /* Device returned QUEUE_FULL. */