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usb: musb: do not use dma for control transfers

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The Inventra DMA engine used with the MUSB controller in many
SoCs cannot use DMA for control transfers on EP0, but can use
DMA for all other transfers.

The USB core maps urbs for DMA if hcd->self.uses_dma is true.
(hcd->self.uses_dma is true for MUSB as well).

Split the uses_dma flag into two - one that says if the
controller needs to use PIO for control transfers, and
another which says if the controller uses DMA (for all
other transfers).

Also, populate this flag for all MUSB by default.

(Tested on OMAP3 and OMAP4 boards, with EHCI and MUSB HCDs
simultaneously in use).

Signed-off-by: Maulik Mankad <x0082077@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
Cc: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Anand Gadiyar
2010-11-18 18:54:17 +05:30
committed by Felipe Balbi
parent bb324b0816
commit 07a8cdd2bb
4 changed files with 13 additions and 0 deletions
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2
drivers/usb/core/hcd.c
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@@ -1330,6 +1330,8 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
*/
if (usb_endpoint_xfer_control(&urb->ep->desc)) {
if (hcd->self.uses_pio_for_control)
return ret;
if (hcd->self.uses_dma) {
urb->setup_dma = dma_map_single(
hcd->self.controller,