Re: [PATCH v1 4/5] media: rkvdec: Re-enable H.264 error detection

Nicolas Dufresne
2022-06-10T16:24:01Z

Le vendredi 10 juin 2022 à 16:20 +0300, Dan Carpenter a écrit :
> On Fri, Jun 10, 2022 at 08:52:14AM -0400, Nicolas Dufresne wrote:
> > This re-enables H.264 error detection, but using the other error mode.
> > In that mode, the decoder will skip over the error macro-block or
> > slices and complete the decoding. As a side effect, the error status
> > is not set in the interrupt status register, and instead errors are
> > detected per format. Using this mode workaround the issue that the
> > HW get stuck in error stated and allow reporting that some corruption
> > may be present in the buffer returned to userland.
> >
> > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> > ---
> > drivers/staging/media/rkvdec/rkvdec-h264.c | 23 +++++++++++++++++++---
> > 1 file changed, 20 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/staging/media/rkvdec/rkvdec-h264.c b/drivers/staging/media/rkvdec/rkvdec-h264.c
> > index 55596ce6bb6e..60a89918e2c1 100644
> > --- a/drivers/staging/media/rkvdec/rkvdec-h264.c
> > +++ b/drivers/staging/media/rkvdec/rkvdec-h264.c
> > @@ -1175,14 +1175,15 @@ static int rkvdec_h264_run(struct rkvdec_ctx *ctx)
> >
> > schedule_delayed_work(&rkvdec->watchdog_work, msecs_to_jiffies(2000));
> >
> > - writel(0, rkvdec->regs + RKVDEC_REG_STRMD_ERR_EN);
> > - writel(0, rkvdec->regs + RKVDEC_REG_H264_ERR_E);
> > + writel(0xffffffff, rkvdec->regs + RKVDEC_REG_STRMD_ERR_EN);
> > + writel(0xffffffff, rkvdec->regs + RKVDEC_REG_H264_ERR_E);
>
> This reverts the changes in patch 1/5. Could we just skip patch 1/5
> instead?

As documented, this is for back-porting purpose. The first patch is what has
been running for 7 years in Chromebook, so I'm fully confident it is safe to
backport it into our stable kernel. The second is like a new feature, which I'm
confident works, but didn't get as much testing as I just wrote it. So what I'm
doing here is giving a same thing to backport, and a better fix for the next
kernel. You are otherwise right that this will revert it.

Nicolas