6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> commit c3070f080f9ba18dea92eaa21730f7ab85b5c8f4 upstream. 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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/display/skl_scaler.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/display/skl_scaler.c +++ b/drivers/gpu/drm/i915/display/skl_scaler.c @@ -504,7 +504,6 @@ int intel_atomic_setup_scalers(struct dr { 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; @@ -536,6 +535,7 @@ int intel_atomic_setup_scalers(struct dr /* 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;
