On Sat, Mar 27, 2021 at 02:59:45AM +0200, Ville Syrjala wrote:

From: Ville Syrjälä ville.syrjala@linux.intel.com

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@intel.com

Cc: stable@vger.kernel.org Cc: Stanislav Lisovskiy stanislav.lisovskiy@intel.com Fixes: dbf71381d733 ("drm/i915: Nuke intel_atomic_crtc_state_for_each_plane_state() from skl+ wm code") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com

---

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