Re: [Freedreno] [PATCH v3] drm/msm/mdp5: stop overriding drvdata

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 10/27/2022 12:56 PM, Dmitry Baryshkov wrote:
> On 27/10/2022 21:30, Abhinav Kumar wrote:
> > On 10/24/2022 8:26 AM, 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@xxxxxxxxxx>
> > > ---
> > > Abhinav, Rob, please pick this for -fixes.
> > >
> > > This is an updated version of [1]. Fixed the read_mdp_hw_revision()
> > > function. PM runtime isn't available at the moment, as priv->kms is not
> > > set.
> > >
> > > [1] https://patchwork.freedesktop.org/patch/490326/?series=105392&rev=1
> > >
> > > Changes since v2:
> > > - Removed the clause checking whether mdp5_enable() has failed (it can
> > >    not fail, noted by Abhinav)
> > >
> > > Changes since v1:
> > > - Expanded the patch to also handle the read_mdp_hw_revision() and also
> > >    to move pm enablement to the place where the pm_runtime can actually
> > >    be used.
> > >
> > > ---
> > >   drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 32 +++++++++++++-----------
> > >   1 file changed, 17 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c 
> > > b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> > > index b0d21838a134..b46f983f2b46 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
> > > @@ -519,9 +519,10 @@ static void read_mdp_hw_revision(struct mdp5_kms 
> > > *mdp5_kms,
> > >       struct device *dev = &mdp5_kms->pdev->dev;
> > >       u32 version;
> > > -    pm_runtime_get_sync(dev);
> > > +    /* Manually enable the MDP5, as pm runtime isn't usable yet. */
> > > +    mdp5_enable(mdp5_kms);
> > >       version = mdp5_read(mdp5_kms, REG_MDP5_HW_VERSION);
> > > -    pm_runtime_put_sync(dev);
> > > +    mdp5_disable(mdp5_kms);
> >
> > Please correct me if wrong here, if we bypass the pm to enable the 
> > clocks explicitly here, are we still guaranteed about GDSC to be ON?
>
> The gdsc is tied to the mdss device, not to mdp5. So the gdsc will be 
> enabled, because for mdp5 to probe the mdss device also should be powered.

Ok, thanks for clarifying.

LGTM,

Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> > >       *major = FIELD(version, MDP5_HW_VERSION_MAJOR);
> > >       *minor = FIELD(version, MDP5_HW_VERSION_MINOR);
> > > @@ -559,6 +560,8 @@ static int mdp5_kms_init(struct drm_device *dev)
> > >       int irq, i, ret;
> > >       ret = mdp5_init(to_platform_device(dev->dev), dev);
> > > +    if (ret)
> > > +        return ret;
> > >       /* priv->kms would have been populated by the MDP5 driver */
> > >       kms = priv->kms;
> > > @@ -632,9 +635,8 @@ 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)
> > > @@ -648,7 +650,7 @@ 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);
> > > @@ -797,8 +799,6 @@ 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;
> > > @@ -839,9 +839,6 @@ static int mdp5_init(struct platform_device 
> > > *pdev, struct drm_device *dev)
> > >        */
> > >       clk_set_rate(mdp5_kms->core_clk, 200000000);
> > > -    pm_runtime_enable(&pdev->dev);
> > > -    mdp5_kms->rpm_enabled = true;
> > > -
> > >       read_mdp_hw_revision(mdp5_kms, &major, &minor);
> > >       mdp5_kms->cfg = mdp5_cfg_init(mdp5_kms, major, minor);
> > > @@ -893,10 +890,13 @@ static int mdp5_init(struct platform_device 
> > > *pdev, struct drm_device *dev)
> > >       /* set uninit-ed kms */
> > >       priv->kms = &mdp5_kms->base.base;
> > > +    pm_runtime_enable(&pdev->dev);
> > > +    mdp5_kms->rpm_enabled = true;
> > > +
> > >       return 0;
> > >   fail:
> > >       if (mdp5_kms)
> > > -        mdp5_destroy(pdev);
> > > +        mdp5_destroy(mdp5_kms);
> > >       return ret;
> > >   }
> > > @@ -953,7 +953,8 @@ 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("");
> > > @@ -963,7 +964,8 @@ 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("");