Re: [Freedreno] [PATCH RFC v6 07/10] drm/atomic: Loosen FB atomic checks

[Dmitry Baryshkov]

On 22/09/2023 20:49, Jessica Zhang wrote:
> On 8/29/2023 1:22 AM, Pekka Paalanen wrote:
> > On Mon, 28 Aug 2023 17:05:13 -0700
> > Jessica Zhang <quic_jesszhan@xxxxxxxxxxx> wrote:
> >
> > > Loosen the requirements for atomic and legacy commit so that, in cases
> > > where pixel_source != FB, the commit can still go through.
> > >
> > > This includes adding framebuffer NULL checks in other areas to 
> > > account for
> > > FB being NULL when non-FB pixel sources are enabled.
> > >
> > > To disable a plane, the pixel_source must be NONE or the FB must be NULL
> > > if pixel_source == FB.
> > >
> > > Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
> > > ---
> > >   drivers/gpu/drm/drm_atomic.c        | 20 +++++++++++---------
> > >   drivers/gpu/drm/drm_atomic_helper.c | 36 
> > > ++++++++++++++++++++----------------
> > >   include/drm/drm_atomic_helper.h     |  4 ++--
> > >   include/drm/drm_plane.h             | 29 +++++++++++++++++++++++++++++
> > >   4 files changed, 62 insertions(+), 27 deletions(-)
> >
> > ...
> >
> > > diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> > > index a58f84b6bd5e..4c5b7bcdb25c 100644
> > > --- a/include/drm/drm_plane.h
> > > +++ b/include/drm/drm_plane.h
> > > @@ -992,6 +992,35 @@ static inline struct drm_plane 
> > > *drm_plane_find(struct drm_device *dev,
> > >   #define drm_for_each_plane(plane, dev) \
> > >       list_for_each_entry(plane, &(dev)->mode_config.plane_list, head)
> > > +/**
> > > + * drm_plane_solid_fill_enabled - Check if solid fill is enabled on 
> > > plane
> > > + * @state: plane state
> > > + *
> > > + * Returns:
> > > + * Whether the plane has been assigned a solid_fill_blob
> > > + */
> > > +static inline bool drm_plane_solid_fill_enabled(struct 
> > > drm_plane_state *state)
> > > +{
> > > +    if (!state)
> > > +        return false;
> > > +    return state->pixel_source == DRM_PLANE_PIXEL_SOURCE_SOLID_FILL 
> > > && state->solid_fill_blob;
> > > +}
> > > +
> > > +static inline bool drm_plane_has_visible_data(const struct 
> > > drm_plane_state *state)
> > > +{
> > > +    switch (state->pixel_source) {
> > > +    case DRM_PLANE_PIXEL_SOURCE_NONE:
> > > +        return false;
> > > +    case DRM_PLANE_PIXEL_SOURCE_SOLID_FILL:
> > > +        return state->solid_fill_blob != NULL;
> >
> > This reminds me, new UAPI docs did not say what the requirements are for
> > choosing solid fill pixel source. Is the atomic commit rejected if
> > pixel source is solid fill, but solid_fill property has no blob?
>
> Hi Pekka,
>
> Yes, if pixel_source is solid_fill and the solid_fill property blob 
> isn't set, the atomic commit should throw an error.
>
> Will document this in the UAPI.

I don't see a corresponding error check in atomic_check() functions. 
Could you please check that there is one, as you are updating the uAPI.

> Thanks,
>
> Jessica Zhang
>
> > This should be doc'd.
> >
> >
> > Thanks,
> > pq
> >
> > > +    case DRM_PLANE_PIXEL_SOURCE_FB:
> > > +    default:
> > > +        WARN_ON(state->pixel_source != DRM_PLANE_PIXEL_SOURCE_FB);
> > > +    }
> > > +
> > > +    return state->fb != NULL;
> > > +}
> > > +
> > >   bool drm_any_plane_has_format(struct drm_device *dev,
> > >                     u32 format, u64 modifier);

--
With best wishes
Dmitry