drm/i915/cdclk: Do cdclk post plane programming later

We currently call intel_set_cdclk_post_plane_update() far
too early. When pipes are active during the reprogramming
the current spot only works for the cd2x divider update
case, as that is synchronize to the pipe's vblank. Squashing
and crawling are not synchronized in any way, so doing the
programming while the pipes/planes are potentially still using
the old hardware state could lead to underruns.

Move the post plane reprgramming to a spot where we know
that the pipes/planes have switched over the new hardware
state.

Cc: stable@vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250218211913.27867-2-ville.syrjala@linux.intel.com
Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
(cherry picked from commit fb64f5568c0e0b5730733d70a012ae26b1a55815)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 41128469f12a219584ad41075ffc485deefbf2f1..c9dcf2bbd4c730e3a502c15999bf4878dc3ef550 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7830,9 +7830,6 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 
        intel_program_dpkgc_latency(state);
 
-       if (state->modeset)
-               intel_set_cdclk_post_plane_update(state);
-
        intel_wait_for_vblank_workers(state);
 
        /* FIXME: We should call drm_atomic_helper_commit_hw_done() here
@@ -7906,6 +7903,8 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
                intel_verify_planes(state);
 
        intel_sagv_post_plane_update(state);
+       if (state->modeset)
+               intel_set_cdclk_post_plane_update(state);
        intel_pmdemand_post_plane_update(state);
 
        drm_atomic_helper_commit_hw_done(&state->base);