[PATCH 3/3] drm/i915/dp: intel_dp connector hook for VRR support

[Manasi Navare]

This defines the get_vrr_support hook for intel DP connector
VRR support is set to true based on the DPCD ignore MSA and
EDID monitor range

Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Nicholas Kazlauskas <Nicholas.Kazlauskas at amd.com>
Cc: Aditya Swarup <aditya.swarup at intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  3 +++
 drivers/gpu/drm/i915/display/intel_dp.c       | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 5e00e611f077..cd37ee6db1ff 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1353,6 +1353,9 @@ struct intel_dp {
 
 	/* Display stream compression testing */
 	bool force_dsc_en;
+
+	/* DP Variable refresh rate/ Adaptive sync support */
+	bool vrr_capable;
 };
 
 enum lspcon_vendor {
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 0a417cd2af2b..ccf5d868b5c1 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5860,6 +5860,24 @@ static int intel_dp_get_modes(struct drm_connector *connector)
 	return 0;
 }
 
+static void intel_dp_get_vrr_support(struct drm_connector *connector)
+{
+	struct intel_dp *intel_dp = intel_attached_dp(to_intel_connector(connector));
+	const struct drm_display_info *info = &connector->display_info;
+	struct drm_i915_private *dev_priv = to_i915(connector->dev);
+
+	/*
+	 * DP Sink is capable of Variable refresh video timings if
+	 * Ignore MSA bit is set in DPCD.
+	 * EDID monitor range also should be atleast 10 for reasonable
+	 * Adaptive sync/ VRR end user experience.
+	 */
+	if (INTEL_GEN(dev_priv) >= 12 &&
+	    drm_dp_sink_is_capable_without_timing_msa(intel_dp->dpcd) &&
+	    info->monitor_range.max_vfreq - info->monitor_range.min_vfreq > 10)
+		intel_dp->vrr_capable = true;
+}
+
 static int
 intel_dp_connector_register(struct drm_connector *connector)
 {
@@ -6756,6 +6774,7 @@ static const struct drm_connector_helper_funcs intel_dp_connector_helper_funcs =
 	.get_modes = intel_dp_get_modes,
 	.mode_valid = intel_dp_mode_valid,
 	.atomic_check = intel_dp_connector_atomic_check,
+	.get_adaptive_sync_support = intel_dp_get_vrr_support,
 };
 
 static const struct drm_encoder_funcs intel_dp_enc_funcs = {
-- 
2.19.1