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authorAnand Gadiyar <gadiyar@ti.com>2010-11-18 18:54:17 +0530
committerFelipe Balbi <balbi@ti.com>2010-11-22 12:55:02 +0200
commit07a8cdd2bb17a4da68136d963b8bc71959bd31a5 (patch)
treefbc64d9842b38848ee7b4d410bab626ff2abd893 /drivers/usb/core
parentbb324b08165d5656d221af013ed9994a54e455be (diff)
downloadtalos-obmc-linux-07a8cdd2bb17a4da68136d963b8bc71959bd31a5.tar.gz
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usb: musb: do not use dma for control transfers
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>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/hcd.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 61800f77dac8..ced846ac4141 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -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,
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