For rx transfers, if dma code can not handle a usb request due to alignment or size threshold, buffers must be unmapped before calling musb_read_fifo(). This is important for platforms with outer-cache due to the following patch: commit 2ffe2da3e71652d4f4cae19539b5c78c2a239136 Author: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> Date: Sat Oct 31 16:52:16 2009 +0000 ARM: dma-mapping: fix for speculative prefetching Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@xxxxxxxxxxxxxx> --- This patch is based on git://gitorious.org/usb/usb.git musb-hw drivers/usb/musb/musb_gadget.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index 7ee8467..238f656 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -765,6 +765,10 @@ static void rxstate(struct musb *musb, struct musb_request *req) return; } #endif + /* Some how DMA is not possible. Unmap + * buffers before continuing with PIO mode. + */ + musb_dma_unmap_request(musb, req); musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *) (request->buf + request->actual)); -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
