Re: [Freedreno] [PATCH] drm: improve the documentation of connector hpd ops

[Abhinav Kumar]

On 12/3/2023 10:14 AM, Dmitry Baryshkov wrote:
> On Sun, 3 Dec 2023 at 16:24, Laurent Pinchart
> <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
> > Hi Abhinav,
> >
> > Thank you for the patch (and thank to Dmitry for pinging me on IRC, this
> > patch got burried in my inbox).
> >
> > On Wed, Sep 20, 2023 at 01:13:58PM -0700, Abhinav Kumar wrote:
> > > While making the changes in [1], it was noted that the documentation
> > > of the enable_hpd() and disable_hpd() does not make it clear that
> > > these ops should not try to do hpd state maintenance and should only
> > > attempt to enable/disable hpd related hardware for the connector.
> >
> > s/attempt to //
>
> I can probably fix this while applying the patch.

Thank you Laurent and Dmitry.

> > > The state management of these calls to make sure these calls are
> > > balanced is handled by the DRM core and we should keep it that way
> > > to minimize the overhead in the drivers which implement these ops.
> > >
> > > [1]: https://patchwork.freedesktop.org/patch/558387/
> >
> > You could add a
> >
> > Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> >
> > > Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> >
> > > ---
> > >   include/drm/drm_modeset_helper_vtables.h | 10 ++++++++++
> > >   1 file changed, 10 insertions(+)
> > >
> > > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
> > > index e3c3ac615909..a33cf7488737 100644
> > > --- a/include/drm/drm_modeset_helper_vtables.h
> > > +++ b/include/drm/drm_modeset_helper_vtables.h
> > > @@ -1154,6 +1154,11 @@ struct drm_connector_helper_funcs {
> > >         * This operation is optional.
> > >         *
> > >         * This callback is used by the drm_kms_helper_poll_enable() helpers.
> > > +      *
> > > +      * This operation does not need to perform any hpd state tracking as
> > > +      * the DRM core handles that maintenance and ensures the calls to enable
> > > +      * and disable hpd are balanced.
> > > +      *
> > >         */
> > >        void (*enable_hpd)(struct drm_connector *connector);
> > >
> > > @@ -1165,6 +1170,11 @@ struct drm_connector_helper_funcs {
> > >         * This operation is optional.
> > >         *
> > >         * This callback is used by the drm_kms_helper_poll_disable() helpers.
> > > +      *
> > > +      * This operation does not need to perform any hpd state tracking as
> > > +      * the DRM core handles that maintenance and ensures the calls to enable
> > > +      * and disable hpd are balanced.
> > > +      *
> > >         */
> > >        void (*disable_hpd)(struct drm_connector *connector);
> > >   };
> >
> > --
> > Regards,
> >
> > Laurent Pinchart