drm/i915/mst: Wait for ACT sent before enabling the pipe

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@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200507144125.2458-1-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 74559379384a8152e49007be059783dd9979da7d..8c732418a33fc08f9e21b4f48961a9aa51414f13 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -512,10 +512,6 @@ 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);
 
@@ -526,6 +522,11 @@ 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);
 }