Hi, Please don't top-posting. On Fri, Aug 03, 2018 at 06:25:50AM +0000, Alexey Spirkov wrote: > Hi, Bin, > > Thanks for note, but what do you think - is 'dma_mapping_error' > checking still needed before call of unmap_dma_buffer? If yes than > I'll check DMA usage in this check instead of is_buffer_map. No, unmap_dma_buffer() can be called unconditionally here because unmap_dma_buffer() already calls is_buffer_mapped() internally. So my comment below is to remove the 'if' condition check you modified. Regards, -Bin. > > Best regards, > Alexey Spirkov > > -----Original Message----- > From: Bin Liu <b-liu@xxxxxx> > Sent: Thursday, August 2, 2018 7:15 PM > To: Alexey Spirkov <AlexeiS@xxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx; andrew@xxxxxxxxxx > Subject: Re: [PATCH] Fix memory issue in non-DMA mode for MUSB gadget > > Hi, > > On Thu, Jul 26, 2018 at 12:52:57PM +0000, Alexey Spirkov wrote: > > dma_mapping_error function unable to works in PowerPC arch when MUSB > > do not use DMA (illegal memory access). Proposed patch replace its > > usage to usual define for checking DMA mapping. > > > > Signed-off-by: Alexey Spirkov <alexeis@xxxxxxxxxxxx> > > --- > > drivers/usb/musb/musb_gadget.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/usb/musb/musb_gadget.c > > b/drivers/usb/musb/musb_gadget.c index eae8b1b..3bc7c25 100644 > > --- a/drivers/usb/musb/musb_gadget.c > > +++ b/drivers/usb/musb/musb_gadget.c > > @@ -140,7 +140,7 @@ __acquires(ep->musb->lock) > > ep->busy = 1; > > spin_unlock(&musb->lock); > > > > - if (!dma_mapping_error(&musb->g.dev, request->dma)) > > + if (req && is_buffer_mapped(req)) > > unmap_dma_buffer() checks for is_buffer_mapped(), so this line can be dropped. > > > unmap_dma_buffer(req, musb); > > > > trace_musb_req_gb(req); > > Regards, > -Bin. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
