usb-storage: Fix devices that cannot handle 32k transfers

When a device cannot handle the smallest previously limited transfer
size (64 blocks) without stalling, limit the device to the amount of
packets that fit in a platform native page.

The lowest possible limit is PAGE_CACHE_SIZE, so if the device is ever
used on a platform that has larger than 8K pages, you lose unless you
can convince the device firmware folks to fix the issue.

Cc: Mathew Dharm <mdharm-scsi@one-eyed-alien.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Doug Maxey <dwm@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 1 deletions

diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h
index 1b792b9286ba..a417b09b8b3d 100644
--- a/include/linux/usb_usual.h
+++ b/include/linux/usb_usual.h
@@ -48,7 +48,10 @@
         US_FLAG(IGNORE_DEVICE,  0x00000800)                     \
                 /* Don't claim device */                        \
         US_FLAG(CAPACITY_HEURISTICS,    0x00001000)             \
-                /* sometimes sizes is too big */
+                /* sometimes sizes is too big */                \
+        US_FLAG(MAX_SECTORS_MIN,0x00002000)                     \
+                /* Sets max_sectors to arch min */
+
 
 #define US_FLAG(name, value)    US_FL_##name = value ,
 enum { US_DO_ALL_FLAGS };