Buffer is mapped to dma when dma channel is allocated. buffer needs to be unmapped when fallback to PIO mode if dma channel_program fails. g_ether use to fail on OMAp3630 as there were unaligned buffers being sent. With this patch and [1] g_ether works fine. [1]:http://www.spinics.net/lists/linux-usb/msg38400.html Signed-off-by: Hema HK <hemahk@xxxxxx> Cc: Felipe Balbi <balbi@xxxxxx> --- Patch based on Linux 2.6.37-rc1 [Fixed the regression issue reported] drivers/usb/musb/musb_gadget.c | 122 +++++++++++++++++++++++++++------------- 1 files changed, 82 insertions(+), 40 deletions(-) Index: linux-2.6/drivers/usb/musb/musb_gadget.c =================================================================== --- linux-2.6.orig/drivers/usb/musb/musb_gadget.c +++ linux-2.6/drivers/usb/musb/musb_gadget.c @@ -92,6 +92,59 @@ /* ----------------------------------------------------------------------- */ +/* Maps the buffer to dma */ + +static inline void map_dma_buffer(struct musb_request *request, + struct musb *musb) +{ + if (request->request.dma == DMA_ADDR_INVALID) { + request->request.dma = dma_map_single( + musb->controller, + request->request.buf, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + request->mapped = 1; + } else { + dma_sync_single_for_device(musb->controller, + request->request.dma, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + request->mapped = 0; + } +} + +/* Unmap the buffer from dma and maps it back to cpu */ +static inline void unmap_dma_buffer(struct musb_request *request, + struct musb *musb) +{ + if (request->request.dma == DMA_ADDR_INVALID) { + DBG(20, "not unmapping a never mapped buffer\n"); + return; + } + if (request->mapped) { + dma_unmap_single(musb->controller, + request->request.dma, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + request->request.dma = DMA_ADDR_INVALID; + request->mapped = 0; + } else { + dma_sync_single_for_cpu(musb->controller, + request->request.dma, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + + } +} + /* * Immediately complete a request. * @@ -119,24 +172,8 @@ __acquires(ep->musb->lock) ep->busy = 1; spin_unlock(&musb->lock); - if (is_dma_capable()) { - if (req->mapped) { - dma_unmap_single(musb->controller, - req->request.dma, - req->request.length, - req->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - req->request.dma = DMA_ADDR_INVALID; - req->mapped = 0; - } else if (req->request.dma != DMA_ADDR_INVALID) - dma_sync_single_for_cpu(musb->controller, - req->request.dma, - req->request.length, - req->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - } + if (is_dma_capable() && ep->dma) + unmap_dma_buffer(req, musb); if (request->status == 0) DBG(5, "%s done request %p, %d/%d\n", ep->end_point.name, request, @@ -395,6 +432,13 @@ static void txstate(struct musb *musb, s #endif if (!use_dma) { + /* + * Unmap the dma buffer back to cpu if dma channel + * programming fails + */ + if (is_dma_capable() && musb_ep->dma) + unmap_dma_buffer(req, musb); + musb_write_fifo(musb_ep->hw_ep, fifo_count, (u8 *) (request->buf + request->actual)); request->actual += fifo_count; @@ -713,6 +757,20 @@ static void rxstate(struct musb *musb, s return; } #endif + /* + * Unmap the dma buffer back to cpu if dma channel + * programming fails. This buffer is mapped if the + * channel allocation is successful + */ + if (is_dma_capable() && musb_ep->dma) { + unmap_dma_buffer(req, musb); + + /* Clear DMAENAB for the + * PIO mode transfer + */ + csr &= ~MUSB_RXCSR_DMAENAB; + musb_writew(epio, MUSB_RXCSR, csr); + } musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *) (request->buf + request->actual)); @@ -1150,26 +1208,9 @@ static int musb_gadget_queue(struct usb_ request->epnum = musb_ep->current_epnum; request->tx = musb_ep->is_in; - if (is_dma_capable() && musb_ep->dma) { - if (request->request.dma == DMA_ADDR_INVALID) { - request->request.dma = dma_map_single( - musb->controller, - request->request.buf, - request->request.length, - request->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - request->mapped = 1; - } else { - dma_sync_single_for_device(musb->controller, - request->request.dma, - request->request.length, - request->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - request->mapped = 0; - } - } else + if (is_dma_capable() && musb_ep->dma) + map_dma_buffer(request, musb); + else request->mapped = 0; spin_lock_irqsave(&musb->lock, lockflags); -- 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
