[PATCH] PATCH: usb-storage: allocate separate sense buffer

This patch is from Alan Stern (as560).  It has been rediffed against a
current tree.

This patch allocates a separate buffer for usb-storage to use when
auto-sensing.  Up to now we have been using the sense buffer embedded in a
scsi_cmnd struct, which is dangerous on hosts that (a) don't do
cache-coherent DMA or (b) have DMA alignment restrictions.

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

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index e89e945fc4a..7ca896a342e 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -636,11 +636,11 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 
                 /* use the new buffer we have */
                 old_request_buffer = srb->request_buffer;
-                srb->request_buffer = srb->sense_buffer;
+                srb->request_buffer = us->sensebuf;
 
                 /* set the buffer length for transfer */
                 old_request_bufflen = srb->request_bufflen;
-                srb->request_bufflen = 18;
+                srb->request_bufflen = US_SENSE_SIZE;
 
                 /* set up for no scatter-gather use */
                 old_sg = srb->use_sg;
@@ -652,6 +652,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
                 temp_result = us->transport(us->srb, us);
 
                 /* let's clean up right away */
+                memcpy(srb->sense_buffer, us->sensebuf, US_SENSE_SIZE);
                 srb->resid = old_resid;
                 srb->request_buffer = old_request_buffer;
                 srb->request_bufflen = old_request_bufflen;