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From balbi@ti.com Tue Oct 5 13:29:53 2010
From: Felipe Balbi <balbi@ti.com>
To: Greg KH <greg@kroah.com>
Cc: Linux USB Mailing List <linux-usb@vger.kernel.org>,
Hema HK <hemahk@ti.com>, Felipe Balbi <balbi@ti.com>
Subject: usb: musb: gadget: Unmapping the dma buffer when switching to PIO mode
Date: Fri, 24 Sep 2010 13:44:08 +0300
Message-Id: <1285325055-1247-8-git-send-email-balbi@ti.com>
From: Hema HK <hemahk@ti.com>
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@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/usb/musb/musb_gadget.c | 122 +++++++++++++++++++++++++++--------------
1 file changed, 82 insertions(+), 40 deletions(-)
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -92,6 +92,60 @@
/* ----------------------------------------------------------------------- */
+/* 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 +173,8 @@ __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,
@@ -298,7 +336,7 @@ static void txstate(struct musb *musb, s
csr);
#ifndef CONFIG_MUSB_PIO_ONLY
- if (is_dma_capable() && musb_ep->dma) {
+ if (is_dma_capable() && !musb_ep->dma && musb->dma_controller) {
struct dma_controller *c = musb->dma_controller;
size_t request_size;
@@ -395,6 +433,13 @@ 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 +756,20 @@ 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));
@@ -1153,28 +1212,11 @@ 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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