Hello.
HEMA HK wrote:
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>
---
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 +92,51 @@
/* ----------------------------------------------------------------------- */
+/* Mapping unmapping the buffer to and from dma */
+
+static inline void map_dma_buffer(struct musb_request *request,
+ struct, musb *musb, bool map)
+{
+ if (map) {
+ 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 (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);
+
+ }
+}
I don't think it's really a good idea to have single function called
map_dma_buffer() that both maps and unmaps a buffer. Why not have two
separate functions?
@@ -711,6 +748,12 @@ 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())
So, which indentation level is correct, that one of the comment, aor
that one of the following code?
+ map_dma_buffer(req, musb, false);
musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
(request->buf + request->actual));
WBR, Sergei
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