On Tue, Apr 13, 2021 at 11:49:01AM +0200, Daniel Vetter wrote:
> Since
> 
> commit 890880ddfdbe256083170866e49c87618b706ac7
> Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> Date:   Fri Jan 4 09:56:10 2019 +0100
> 
>     drm: Auto-set allow_fb_modifiers when given modifiers at plane init
> 
> this is done automatically as part of plane init, if drivers set the
> modifier list correctly. Which is the case here.
> 
> It was slightly inconsistently though, since planes with only linear
> modifier support haven't listed that explicitly. Fix that, and cc:
> stable to allow userspace to rely on this. Again don't backport
> further than where Paul's patch got added.
> 
> Cc: stable@vger.kernel.org # v5.1 +
> Cc: Pekka Paalanen <pekka.paalanen@collabora.com>
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Jonathan Hunter <jonathanh@nvidia.com>
> Cc: linux-tegra@vger.kernel.org
> ---
>  drivers/gpu/drm/tegra/dc.c  | 10 ++++++++--
>  drivers/gpu/drm/tegra/drm.c |  2 --
>  2 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
> index c9385cfd0fc1..f9845a50f866 100644
> --- a/drivers/gpu/drm/tegra/dc.c
> +++ b/drivers/gpu/drm/tegra/dc.c
> @@ -959,6 +959,11 @@ static const struct drm_plane_helper_funcs tegra_cursor_plane_helper_funcs = {
>  	.atomic_disable = tegra_cursor_atomic_disable,
>  };
>  
> +static const uint64_t linear_modifiers[] = {
> +	DRM_FORMAT_MOD_LINEAR,
> +	DRM_FORMAT_MOD_INVALID
> +};
> +
>  static struct drm_plane *tegra_dc_cursor_plane_create(struct drm_device *drm,
>  						      struct tegra_dc *dc)
>  {
> @@ -987,7 +992,7 @@ static struct drm_plane *tegra_dc_cursor_plane_create(struct drm_device *drm,
>  
>  	err = drm_universal_plane_init(drm, &plane->base, possible_crtcs,
>  				       &tegra_plane_funcs, formats,
> -				       num_formats, NULL,
> +				       num_formats, linear_modifiers,
>  				       DRM_PLANE_TYPE_CURSOR, NULL);
>  	if (err < 0) {
>  		kfree(plane);
> @@ -1106,7 +1111,8 @@ static struct drm_plane *tegra_dc_overlay_plane_create(struct drm_device *drm,
>  
>  	err = drm_universal_plane_init(drm, &plane->base, possible_crtcs,
>  				       &tegra_plane_funcs, formats,
> -				       num_formats, NULL, type, NULL);
> +				       num_formats, linear_modifiers,
> +				       type, NULL);

I think we can do better than linear_modifiers for overlay planes, but
given that this doesn't change existing behaviour, I'll do that in a
separate patch.

Acked-by: Thierry Reding <treding@nvidia.com>