[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, 2 insertions, 0 deletions

diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h
index a195adae57b6..dfa4dc71dd3e 100644
--- a/drivers/usb/storage/usb.h
+++ b/drivers/usb/storage/usb.h
@@ -117,6 +117,7 @@ enum { US_DO_ALL_FLAGS };
  */
 
 #define US_IOBUF_SIZE           64      /* Size of the DMA-mapped I/O buffer */
+#define US_SENSE_SIZE           18      /* Size of the autosense data buffer */
 
 typedef int (*trans_cmnd)(struct scsi_cmnd *, struct us_data*);
 typedef int (*trans_reset)(struct us_data*);
@@ -168,6 +169,7 @@ struct us_data {
         struct usb_ctrlrequest  *cr;             /* control requests     */
         struct usb_sg_request   current_sg;      /* scatter-gather req.  */
         unsigned char           *iobuf;          /* I/O buffer           */
+        unsigned char           *sensebuf;       /* sense data buffer    */
         dma_addr_t              cr_dma;          /* buffer DMA addresses */
         dma_addr_t              iobuf_dma;