On Tue, 2025-02-18 at 23:18 +0200, Ville Syrjala wrote:

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

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

---

drivers/gpu/drm/i915/display/intel_display.c | 5 ++---  1 file changed, 2 insertions(+), 3 deletions(-)

Reviewed-by: Vinod Govindapillai vinod.govindapillai@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 065fdf6dbb88..cb9c6ad3aa11 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -7527,9 +7527,6 @@ 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 @@ -7606,6 +7603,8 @@ 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);