[Intel-gfx] [RFC 6/8] drm/i915: Check for FRL training before DP Link training

[Ankit Nautiyal]

This patch calls functions to check FRL training requirements
for an HDMI2.1 sink, when connected through PCON.
The call is made before the DP link training. In case FRL is not
required or failure during FRL training, the TMDS mode is selected
for the pcon.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 2 ++
 drivers/gpu/drm/i915/display/intel_dp.c  | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index b4c520348b3b..94c8a7dab97b 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3489,6 +3489,8 @@ static void tgl_ddi_pre_enable_dp(struct intel_atomic_state *state,
 	if (!is_mst)
 		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
 
+	intel_dp_check_frl_training(intel_dp);
+
 	intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
 	/*
 	 * DDI FEC: "anticipates enabling FEC encoding sets the FEC_READY bit
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index fd30e025a09e..d3b67c7123d8 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4165,6 +4165,7 @@ static void intel_enable_dp(struct intel_atomic_state *state,
 
 	intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
 	intel_dp_configure_protocol_converter(intel_dp);
+	intel_dp_check_frl_training(intel_dp);
 	intel_dp_start_link_train(intel_dp, pipe_config);
 	intel_dp_stop_link_train(intel_dp, pipe_config);
 
@@ -6099,6 +6100,7 @@ int intel_dp_retrain_link(struct intel_encoder *encoder,
 		    !intel_dp_mst_is_master_trans(crtc_state))
 			continue;
 
+		intel_dp_check_frl_training(intel_dp);
 		intel_dp_start_link_train(intel_dp, crtc_state);
 		intel_dp_stop_link_train(intel_dp, crtc_state);
 		break;
-- 
2.17.1