From: Kishon Vijay Abraham I <kishon@xxxxxx>
musb does not use DMA buffer for ep0 but it uses the same giveback
function *musb_g_giveback* for all endpoints (*musb_g_ep0_giveback* calls
*musb_g_giveback*). So for ep0 case request.dma will be '0'
and will result in kernel OOPS if tried to *unmap_dma_buffer* for requests in
ep0. Fixed it by doing *unmap_dma_buffer* only for valid DMA addr and
checking that musb_ep->dma is valid when unmapping.
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
Hi Kishon, this is how your patch looks like now,
do you think it's alright ? Since map_dma_buffer() checks
that musb_ep->dma is valid, I think we should do the same
thing when unmapping, what do you think ?
drivers/usb/musb/musb_gadget.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index be18537..d9712bf 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -141,7 +141,7 @@ static inline void map_dma_buffer(struct musb_request *request,
static inline void unmap_dma_buffer(struct musb_request *request,
struct musb *musb)
{
- if (!is_buffer_mapped(request))
+ if (!is_buffer_mapped(request) || !musb_ep->dma)
return;
if (request->request.dma == DMA_ADDR_INVALID) {
@@ -195,7 +195,10 @@ __acquires(ep->musb->lock)
ep->busy = 1;
spin_unlock(&musb->lock);
- unmap_dma_buffer(req, musb);
+
+ if (!dma_mapping_error(request->dma))
+ unmap_dma_buffer(req, musb);
+
if (request->status == 0)
dev_dbg(musb->controller, "%s done request %p, %d/%d\n",
ep->end_point.name, request,
--
1.8.2
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