Re: [PATCH v1 2/3] media: cedrus: Set the platform driver data earlier

From: Jernej Škrabec
Date: Sat Aug 20 2022 - 04:25:59 EST


Dne petek, 19. avgust 2022 ob 17:37:20 CEST je Nicolas Dufresne napisal(a):
> Le vendredi 19 août 2022 à 06:17 +0200, Jernej Škrabec a écrit :
> > Dne četrtek, 18. avgust 2022 ob 22:33:07 CEST je Nicolas Dufresne
napisal(a):
> > > From: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> > >
> > > The cedrus_hw_resume() crashes with NULL deference on driver probe if
> > > runtime PM is disabled because it uses platform data that hasn't been
> > > set up yet. Fix this by setting the platform data earlier during probe.
> >
> > Does it even work without PM? Maybe it would be better if Cedrus would
> > select PM in Kconfig.
>
> I cannot comment myself on this, but it does not seem to invalidate this
> Dmitry's fix.

If NULL pointer dereference happens only when PM is disabled, then it does. I
have PM always enabled and I never experienced above issue.

Best regards,
Jernej

>
> > Best regards,
> > Jernej
> >
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> > > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
> > > ---
> > >
> > > drivers/staging/media/sunxi/cedrus/cedrus.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c
> > > b/drivers/staging/media/sunxi/cedrus/cedrus.c index
> > > 960a0130cd620..55c54dfdc585c 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus.c
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
> > > @@ -448,6 +448,8 @@ static int cedrus_probe(struct platform_device
> > > *pdev)
> > >
> > > if (!dev)
> > >
> > > return -ENOMEM;
> > >
> > > + platform_set_drvdata(pdev, dev);
> > > +
> > >
> > > dev->vfd = cedrus_video_device;
> > > dev->dev = &pdev->dev;
> > > dev->pdev = pdev;
> > >
> > > @@ -521,8 +523,6 @@ static int cedrus_probe(struct platform_device
> > > *pdev)
> > >
> > > goto err_m2m_mc;
> > >
> > > }
> > >
> > > - platform_set_drvdata(pdev, dev);
> > > -
> > >
> > > return 0;
> > >
> > > err_m2m_mc: