On Sat, Mar 27, 2021 at 02:59:45AM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> Don't zero out the watermarks for the Y plane since we've already
> computed them when computing the UV plane's watermarks (since the
> UV plane always appears before ethe Y plane when iterating through
> the planes).
>
> This leads to allocating no DDB for the Y plane since .min_ddb_alloc
> also gets zeroed. And that of course leads to underruns when scanning
> out planar formats.
>
> We really need to re-enable the pre-merge pixel format tests or else
> I'll just keep breaking this stuff...
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> Fixes: dbf71381d733 ("drm/i915: Nuke intel_atomic_crtc_state_for_each_plane_state() from skl+ wm code")
> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/intel_pm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index b2aede2be89d..49c19acdb7c6 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -5511,12 +5511,12 @@ static int icl_build_plane_wm(struct intel_crtc_state *crtc_state,
> struct skl_plane_wm *wm = &crtc_state->wm.skl.raw.planes[plane_id];
> int ret;
>
> - memset(wm, 0, sizeof(*wm));
> -
> /* Watermarks calculated in master */
> if (plane_state->planar_slave)
> return 0;
>
> + memset(wm, 0, sizeof(*wm));
> +
> if (plane_state->planar_linked_plane) {
> const struct drm_framebuffer *fb = plane_state->hw.fb;
> enum plane_id y_plane_id = plane_state->planar_linked_plane->id;
> --
> 2.26.2
>
