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USB: remove uses of URB_NO_SETUP_DMA_MAP

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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>
This commit is contained in:
Alan Stern
2010-03-05 15:10:17 -05:00
committed by Greg Kroah-Hartman
parent 749da5f82f
commit 0ede76fcec
13 changed files with 27 additions and 75 deletions
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15
drivers/usb/storage/usb.c
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@@ -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);