Hi Vinod,
On Mon, 29 Apr 2019 at 19:36, Vinod Koul <vkoul@xxxxxxxxxx> wrote:
>
> On 15-04-19, 20:14, Baolin Wang wrote:
> > We will get a NULL virtual descriptor by vchan_find_desc() when the descriptor
> > has been submitted, that will crash the kernel when getting the engine status.
>
> No that is wrong, status is for descriptor and not engine!
Sure, will fix the commit message.
>
> > In this case, since the descriptor has been submitted, which means the pointer
> > 'schan->cur_desc' will point to the current descriptor, then we can use
> > 'schan->cur_desc' to get the engine status to avoid this issue.
>
> Nope, since the descriptor is completed, you return with residue as 0
> and DMA_COMPLETE status!
No, the descriptor is not completed now. If it is completed, we will
return 0 with DMA_COMPLETE status. But now the descriptor is on
progress, we should get the descriptor to return current residue.
Sorry for confusing description.
>
> >
> > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
> > ---
> > drivers/dma/sprd-dma.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
> > index 48431e2..e29342a 100644
> > --- a/drivers/dma/sprd-dma.c
> > +++ b/drivers/dma/sprd-dma.c
> > @@ -625,7 +625,7 @@ static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
> > else
> > pos = 0;
> > } else if (schan->cur_desc && schan->cur_desc->vd.tx.cookie == cookie) {
> > - struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
> > + struct sprd_dma_desc *sdesc = schan->cur_desc;
> >
> > if (sdesc->dir == DMA_DEV_TO_MEM)
> > pos = sprd_dma_get_dst_addr(schan);
> > --
> > 1.7.9.5
>
> --
> ~Vinod
--
Baolin Wang
Best Regards
