[Intel-gfx] [PATCH 1/2] drm/i915: Reject 90/270 degree rotated initial fbs

[Chris Wilson]

Quoting Ville Syrjala (2020-10-20 20:43:29)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> We don't currently handle the initial fb readout correctly
> for 90/270 degree rotated scanout. Reject it.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 60bacdbe7f92..fd0103f6cc95 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -10696,6 +10696,10 @@ skl_get_initial_plane_config(struct intel_crtc *crtc,
>             val & PLANE_CTL_FLIP_HORIZONTAL)
>                 plane_config->rotation |= DRM_MODE_REFLECT_X;
>  
> +       /* 90/270 degree rotation would require extra work */
> +       if (drm_rotation_90_or_270(plane_config->rotation))
> +               goto error;

Only skl+ have 90/270 rotation so i9xx_get_initial_plane_config() does
not require the check.
error: seems valid

And as evidenced by the next patch, plenty needs to be done to handle
90/270.

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

I expect you intend cc:stable for sanity?
-Chris