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

drivers/usb/storage/transport.c

+3 −2
Original line number Diff line number Diff line
@@ -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;

drivers/usb/storage/usb.c

+8 −0
Original line number Diff line number Diff line
@@ -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,

drivers/usb/storage/usb.h

+2 −0
Original line number Diff line number Diff line
@@ -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;