Hi,
Any comments for the below patch?
Regards,
Hema
>-----Original Message-----
>From: Kalliguddi, Hema
>Sent: Wednesday, May 19, 2010 2:52 PM
>To: linux-usb@xxxxxxxxxxxxxxx
>Cc: Kalliguddi, Hema
>Subject: [PATCH v6 1/2] usb: musb: Unmapping the dma buffer
>when switching to PIO mode
>
>From: Hema HK <hemahk@xxxxxx>
>
>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.
>
>Signed-off-by: Hema HK <hemahk@xxxxxx>
>---
>Based off V2.6.34 + gregkh-07-usb-2.6.34.patch
>
>Addressed some more review comments from Ajay and Sergei.
>
>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 +92,56 @@
>
> /*
>---------------------------------------------------------------
>-------- */
>
>+/* 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->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 +169,8 @@ __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,
>@@ -393,6 +427,13 @@ 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;
>@@ -711,6 +752,13 @@ 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())
>+ unmap_dma_buffer(req, musb);
>
> musb_read_fifo(musb_ep->hw_ep,
>fifo_count, (u8 *)
> (request->buf +
>request->actual));
>@@ -1125,28 +1173,11 @@ 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 (!req->buf) {
>+ if (is_dma_capable() && musb_ep->dma)
>+ map_dma_buffer(request, musb);
>+ else if (!req->buf)
> return -ENODATA;
>- } else
>+ else
> request->mapped = 0;
>
> spin_lock_irqsave(&musb->lock, lockflags);
>--
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