On 29-04-19, 19:49, Baolin Wang wrote:
> Hi Vinod,
>
> On Mon, 29 Apr 2019 at 19:36, Vinod Koul <vk...@kernel.org> 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.
OKay will wait for updated description to understand the fix
>
> >
> > >
> > > Signed-off-by: Baolin Wang <baolin.w...@linaro.org>
> > > ---
> > > 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
--
~Vinod
