On Mon, Mar 18, 2013 at 02:17:52PM +0530, kishon wrote:
> On Monday 18 March 2013 02:12 PM, Felipe Balbi wrote:
> >Hi,
> >
> >On Mon, Mar 18, 2013 at 01:50:55PM +0530, kishon wrote:
> >>>>>@@ -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))
> >>>>
> >>>>this should have been *dma_mapping_error(&musb->g.dev, request->dma)*
> >>>
> >>>indeed :-)
> >>>
> >>>>;-) But this doesn't work quite right. The dma_mapping_error
> >>>>considers only *DMA_ERROR_CODE* as error. Maybe we should have
> >>>>something like this
> >>>>
> >>>>*if (!dma_mapping_error(&musb->g.dev, request->dma) && request->dma)*
> >>>
> >>>won't 'is_buffer_mapped()' take care of the second check ?
> >>
> >>No, it doesn't. Btw you've removed is_buffer_mapped() macro in *usb:
> >>musb: gadget: switch over to usb_gadget_map/unmap_request()* patch..
> >
> >I dropped that patch since MUSB needs a bit more care when switching to
> >generic map/unmap routines. We can do that for v3.11 instead.
>
> Oh ok. Then we need to take care when we have that patch.right, so what about this? commit 06d9db7273c7bd5b07624b313faeea57a4b31056 Author: Kishon Vijay Abraham I <[email protected]> Date: Fri Mar 15 18:58:50 2013 +0530 usb: musb: gadget: do *unmap_dma_buffer* only for valid DMA addr 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 <[email protected]> Signed-off-by: Felipe Balbi <[email protected]> diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index be18537..83edded 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -141,7 +141,9 @@ 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)) + struct musb_ep *musb_ep = request->ep; + + if (!is_buffer_mapped(request) || !musb_ep->dma) return; if (request->request.dma == DMA_ADDR_INVALID) { @@ -195,7 +197,10 @@ __acquires(ep->musb->lock) ep->busy = 1; spin_unlock(&musb->lock); - unmap_dma_buffer(req, musb); + + if (!dma_mapping_error(&musb->g.dev, 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, note that is_buffer_mapped() knows that request->dma is valid or not since request->mapped is set only if dma_map has succeeded. -- balbi
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