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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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3
drivers/usb/storage/usb.h
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@@ -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 */