[PATCH v1 1/4] drm/msm/mdp5: stop overriding drvdata

[Dmitry Baryshkov]

On Wed, 24 Aug 2022 at 04:25, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 6/20/2022 2:30 PM, Dmitry Baryshkov wrote:
> > The rest of the code expects that master's device drvdata is the
> > struct msm_drm_private instance. Do not override the mdp5's drvdata.
> >
> > Fixes: 6874f48bb8b0 ("drm/msm: make mdp5/dpu devices master components")
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
>
> Is this just for consistency across mdp5/dpu drivers?
>
> What issue was seen if mdp5's platform data is overwritten?

I think there was a crash in mdp5_destroy, but I did not capture the
log at the moment.

As you can see, the mdp5_destroy() expects to get mdp5_kms pointer
from the drvdata. However the msm_drv_probe sets the drvdata to
msm_drm_private instance. Boom.

>
> > ---
> >   drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 19 +++++++++----------
> >   1 file changed, 9 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> > index c668a4b27cc6..daf5b5ca7233 100644
> > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> > @@ -203,7 +203,7 @@ static int mdp5_set_split_display(struct msm_kms *kms,
> >                                                         slave_encoder);
> >   }
> >
> > -static void mdp5_destroy(struct platform_device *pdev);
> > +static void mdp5_destroy(struct mdp5_kms *mdp5_kms);
> >
> >   static void mdp5_kms_destroy(struct msm_kms *kms)
> >   {
> > @@ -223,7 +223,7 @@ static void mdp5_kms_destroy(struct msm_kms *kms)
> >       }
> >
> >       mdp_kms_destroy(&mdp5_kms->base);
> > -     mdp5_destroy(mdp5_kms->pdev);
> > +     mdp5_destroy(mdp5_kms);
> >   }
> >
> >   #ifdef CONFIG_DEBUG_FS
> > @@ -651,9 +651,8 @@ static int mdp5_kms_init(struct drm_device *dev)
> >       return ret;
> >   }
> >
> > -static void mdp5_destroy(struct platform_device *pdev)
> > +static void mdp5_destroy(struct mdp5_kms *mdp5_kms)
> >   {
> > -     struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
> >       int i;
> >
> >       if (mdp5_kms->ctlm)
> > @@ -667,7 +666,7 @@ static void mdp5_destroy(struct platform_device *pdev)
> >               kfree(mdp5_kms->intfs[i]);
> >
> >       if (mdp5_kms->rpm_enabled)
> > -             pm_runtime_disable(&pdev->dev);
> > +             pm_runtime_disable(&mdp5_kms->pdev->dev);
> >
> >       drm_atomic_private_obj_fini(&mdp5_kms->glob_state);
> >       drm_modeset_lock_fini(&mdp5_kms->glob_state_lock);
> > @@ -816,8 +815,6 @@ static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)
> >               goto fail;
> >       }
> >
> > -     platform_set_drvdata(pdev, mdp5_kms);
> > -
> >       spin_lock_init(&mdp5_kms->resource_lock);
> >
> >       mdp5_kms->dev = dev;
> > @@ -915,7 +912,7 @@ static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)
> >       return 0;
> >   fail:
> >       if (mdp5_kms)
> > -             mdp5_destroy(pdev);
> > +             mdp5_destroy(mdp5_kms);
> >       return ret;
> >   }
> >
> > @@ -975,7 +972,8 @@ static int mdp5_dev_remove(struct platform_device *pdev)
> >   static __maybe_unused int mdp5_runtime_suspend(struct device *dev)
> >   {
> >       struct platform_device *pdev = to_platform_device(dev);
> > -     struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
> > +     struct msm_drm_private *priv = platform_get_drvdata(pdev);
> > +     struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
> >
> >       DBG("");
> >
> > @@ -985,7 +983,8 @@ static __maybe_unused int mdp5_runtime_suspend(struct device *dev)
> >   static __maybe_unused int mdp5_runtime_resume(struct device *dev)
> >   {
> >       struct platform_device *pdev = to_platform_device(dev);
> > -     struct mdp5_kms *mdp5_kms = platform_get_drvdata(pdev);
> > +     struct msm_drm_private *priv = platform_get_drvdata(pdev);
> > +     struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
> >
> >       DBG("");
> >



-- 
With best wishes
Dmitry