Commit bbafa466 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

[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: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarMatthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent b876aef7
......@@ -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;
......
......@@ -467,6 +467,12 @@ static int associate_dev(struct us_data *us, struct usb_interface *intf)
US_DEBUGP("I/O buffer allocation failed\n");
return -ENOMEM;
}
us->sensebuf = kmalloc(US_SENSE_SIZE, GFP_KERNEL);
if (!us->sensebuf) {
US_DEBUGP("Sense buffer allocation failed\n");
return -ENOMEM;
}
return 0;
}
......@@ -800,6 +806,8 @@ static void dissociate_dev(struct us_data *us)
{
US_DEBUGP("-- %s\n", __FUNCTION__);
kfree(us->sensebuf);
/* Free the device-related DMA-mapped buffers */
if (us->cr)
usb_buffer_free(us->pusb_dev, sizeof(*us->cr), us->cr,
......
......@@ -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;
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment