This is a note to let you know that I've just added the patch titled
drm/i915: Fix intel_atomic_setup_scalers() plane_state handling
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-fix-intel_atomic_setup_scalers-plane_state-.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c1cd9a61fc16fd3135cea0c98e23df3181ee26a9
Author: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Thu Dec 7 21:34:34 2023 +0200
drm/i915: Fix intel_atomic_setup_scalers() plane_state handling
[ Upstream commit c3070f080f9ba18dea92eaa21730f7ab85b5c8f4 ]
Since the plane_state variable is declared outside the scaler_users
loop in intel_atomic_setup_scalers(), and it's never reset back to
NULL inside the loop we may end up calling intel_atomic_setup_scaler()
with a non-NULL plane state for the pipe scaling case. That is bad
because intel_atomic_setup_scaler() determines whether we are doing
plane scaling or pipe scaling based on plane_state!=NULL. The end
result is that we may miscalculate the scaler mode for pipe scaling.
The hardware becomes somewhat upset if we end up in this situation
when scanning out a planar format on a SDR plane. We end up
programming the pipe scaler into planar mode as well, and the
result is a screenfull of garbage.
Fix the situation by making sure we pass the correct plane_state==NULL
when calculating the scaler mode for pipe scaling.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20231207193441.20206-2-ville.syrjala@xxxxxxxxxxxxxxx
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
(cherry picked from commit e81144106e21271c619f0c722a09e27ccb8c043d)
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/i915/display/skl_scaler.c b/drivers/gpu/drm/i915/display/skl_scaler.c
index 83a61efa84395..0b74f91e865d0 100644
--- a/drivers/gpu/drm/i915/display/skl_scaler.c
+++ b/drivers/gpu/drm/i915/display/skl_scaler.c
@@ -493,7 +493,6 @@ int intel_atomic_setup_scalers(struct drm_i915_private *dev_priv,
{
struct drm_plane *plane = NULL;
struct intel_plane *intel_plane;
- struct intel_plane_state *plane_state = NULL;
struct intel_crtc_scaler_state *scaler_state =
&crtc_state->scaler_state;
struct drm_atomic_state *drm_state = crtc_state->uapi.state;
@@ -525,6 +524,7 @@ int intel_atomic_setup_scalers(struct drm_i915_private *dev_priv,
/* walkthrough scaler_users bits and start assigning scalers */
for (i = 0; i < sizeof(scaler_state->scaler_users) * 8; i++) {
+ struct intel_plane_state *plane_state = NULL;
int *scaler_id;
const char *name;
int idx, ret;
