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-rc5
Addressed review comments.
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 +92,58 @@
/* ----------------------------------------------------------------------- */
+/* 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) {
+ printk(" map buffer");
+ 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.
*
@@ -119,23 +171,8 @@ __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",
@@ -198,6 +235,7 @@ static void nuke(struct musb_ep *ep, con
}
}
+
/* ----------------------------------------------------------------------- */
/* Data transfers - pure PIO, pure DMA, or mixed mode */
@@ -393,6 +431,12 @@ 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())
+ 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 +755,12 @@ 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));
@@ -1126,24 +1176,7 @@ static int musb_gadget_queue(struct usb_
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;
- }
+ map_dma_buffer(request, musb);
} else if (!req->buf) {
return -ENODATA;
} else
--
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