[RFC 5/7] 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 4d06178cd76c..cf8a8e2a64f7 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3389,6 +3389,8 @@ 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 3a8e69e5bbfb..b6e53e4f06ee 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4129,6 +4129,7 @@ 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);
 	intel_dp_stop_link_train(intel_dp);
 
@@ -6050,6 +6051,7 @@ int intel_dp_retrain_link(struct intel_encoder *encoder,
 							      intel_crtc_pch_transcoder(crtc), false);
 	}
 
+	intel_dp_check_frl_training(intel_dp);
 	intel_dp_start_link_train(intel_dp);
 	intel_dp_stop_link_train(intel_dp);
 
-- 
2.17.1