USB: remove uses of URB_NO_SETUP_DMA_MAP

This patch (as1350) removes all usages of coherent buffers for USB
control-request setup-packet buffers.  There's no good reason to
reserve coherent memory for these things; control requests are hardly
ever used in large quantity (the major exception is firmware
transfers, and they aren't time-critical).  Furthermore, only seven
drivers used it.  We might as well always use streaming DMA mappings
for setup-packet buffers, and remove some extra complexity from
usbcore.

The DMA-mapping portion of hcd.c is currently in flux.  A separate
patch will be submitted to remove support for URB_NO_SETUP_DMA_MAP
after everything else settles down.  The removal should go smoothly,
as by then nobody will be using it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 6 insertions, 14 deletions

diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index f253edec3bb..44716427c51 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -147,11 +147,9 @@ static int usb_stor_msg_common(struct us_data *us, int timeout)
          * hasn't been mapped for DMA.  Yes, this is clunky, but it's
          * easier than always having the caller tell us whether the
          * transfer buffer has already been mapped. */
-        us->current_urb->transfer_flags = URB_NO_SETUP_DMA_MAP;
         if (us->current_urb->transfer_buffer == us->iobuf)
                 us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
         us->current_urb->transfer_dma = us->iobuf_dma;
-        us->current_urb->setup_dma = us->cr_dma;
 
         /* submit the URB */
         status = usb_submit_urb(us->current_urb, GFP_NOIO);
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index bbeeb92a213..c54a370c76c 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -407,9 +407,8 @@ static int associate_dev(struct us_data *us, struct usb_interface *intf)
         /* Store our private data in the interface */
         usb_set_intfdata(intf, us);
 
-        /* Allocate the device-related DMA-mapped buffers */
-        us->cr = usb_buffer_alloc(us->pusb_dev, sizeof(*us->cr),
-                        GFP_KERNEL, &us->cr_dma);
+        /* Allocate the control/setup and DMA-mapped buffers */
+        us->cr = kmalloc(sizeof(*us->cr), GFP_KERNEL);
         if (!us->cr) {
                 US_DEBUGP("usb_ctrlrequest allocation failed\n");
                 return -ENOMEM;
@@ -757,13 +756,9 @@ static void dissociate_dev(struct us_data *us)
 {
         US_DEBUGP("-- %s\n", __func__);
 
-        /* Free the device-related DMA-mapped buffers */
-        if (us->cr)
-                usb_buffer_free(us->pusb_dev, sizeof(*us->cr), us->cr,
-                                us->cr_dma);
-        if (us->iobuf)
-                usb_buffer_free(us->pusb_dev, US_IOBUF_SIZE, us->iobuf,
-                                us->iobuf_dma);
+        /* Free the buffers */
+        kfree(us->cr);
+        usb_buffer_free(us->pusb_dev, US_IOBUF_SIZE, us->iobuf, us->iobuf_dma);
 
         /* Remove our private data from the interface */
         usb_set_intfdata(us->pusb_intf, NULL);
diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h
index 69717134231..89d3bfff98d 100644
--- a/drivers/usb/storage/usb.h
+++ b/drivers/usb/storage/usb.h
@@ -139,8 +139,7 @@ struct us_data {
         struct usb_ctrlrequest  *cr;             /* control requests     */
         struct usb_sg_request   current_sg;      /* scatter-gather req.  */
         unsigned char           *iobuf;          /* I/O buffer           */
-        dma_addr_t              cr_dma;          /* buffer DMA addresses */
-        dma_addr_t              iobuf_dma;
+        dma_addr_t              iobuf_dma;       /* buffer DMA addresses */
         struct task_struct      *ctl_thread;     /* the control thread   */
 
         /* mutual exclusion and synchronization structures */