[Intel-gfx] [PATCH] drm/i915/mst: Wait for ACT sent before enabling the pipe

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The correct sequence according to bspec is to wait for the ACT sent
status before we turn on the pipe. Make it so.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp_mst.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 4d2384650383..d18b406f2a7d 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -510,10 +510,6 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
 
 	intel_ddi_enable_transcoder_func(encoder, pipe_config);
 
-	intel_enable_pipe(pipe_config);
-
-	intel_crtc_vblank_on(pipe_config);
-
 	drm_dbg_kms(&dev_priv->drm, "active links %d\n",
 		    intel_dp->active_mst_links);
 
@@ -524,6 +520,11 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
 	drm_dp_check_act_status(&intel_dp->mst_mgr);
 
 	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
+
+	intel_enable_pipe(pipe_config);
+
+	intel_crtc_vblank_on(pipe_config);
+
 	if (pipe_config->has_audio)
 		intel_audio_codec_enable(encoder, pipe_config, conn_state);
 }
-- 
2.24.1