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, 7 insertions, 0 deletions

diff --git a/drivers/usb/storage/unusual_devs.h b/drivers/usb/storage/unusual_devs.h
index 2c27721bd259..7bbfd31a9645 100644
--- a/drivers/usb/storage/unusual_devs.h
+++ b/drivers/usb/storage/unusual_devs.h
@@ -376,6 +376,13 @@ UNUSUAL_DEV(  0x04b0, 0x0417, 0x0100, 0x0100,
                 US_SC_DEVICE, US_PR_DEVICE, NULL,
                 US_FL_FIX_CAPACITY),
 
+/* Reported by Doug Maxey (dwm@austin.ibm.com) */
+UNUSUAL_DEV(  0x04b3, 0x4001, 0x0110, 0x0110,
+                "IBM",
+                "IBM RSA2",
+                US_SC_DEVICE, US_PR_CB, NULL,
+                US_FL_MAX_SECTORS_MIN),
+
 /* BENQ DC5330
  * Reported by Manuel Fombuena <mfombuena@ya.com> and
  * Frank Copeland <fjc@thingy.apana.org.au> */