drm/i915/edp: eDP Data Overrride

We need override certain link rates in favour of the next available
higher link rate. The Link rates that need to be overridden are
indicated by a mask in VBT. To make sure these modes are skipped we
don't add them in them in the sink rates array.

--v2
-Update the link rates after we have a final set of link rates [Ankit]
-Break this patch up [Ankit]
-Optimize the assingment during loop [Ankit]

--v3
-Add protection against broken VBTs [Jani]

--v4
-Fix build errors
-Create a seprate function to check if edp data override is selected
and using the correct vbt

--v5
-Use correct number to check the num of edp rates [Ankit]

--v6
-No seprate function check if vbt is broken in the reject rate function
[Jani]

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://lore.kernel.org/r/20250821042653.269227-4-suraj.kandpal@intel.com

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 996edb8deded..bed7cba1ca68 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4313,6 +4313,23 @@ static void intel_edp_mso_init(struct intel_dp *intel_dp)
 }
 
 static void
+intel_edp_set_data_override_rates(struct intel_dp *intel_dp)
+{
+	struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
+	int *sink_rates = intel_dp->sink_rates;
+	int i, count = 0;
+
+	for (i = 0; i < intel_dp->num_sink_rates; i++) {
+		if (intel_bios_encoder_reject_edp_rate(encoder->devdata,
+						       intel_dp->sink_rates[i]))
+			continue;
+
+		sink_rates[count++] = intel_dp->sink_rates[i];
+	}
+	intel_dp->num_sink_rates = count;
+}
+
+static void
 intel_edp_set_sink_rates(struct intel_dp *intel_dp)
 {
 	struct intel_display *display = to_intel_display(intel_dp);
@@ -4362,6 +4379,8 @@ intel_edp_set_sink_rates(struct intel_dp *intel_dp)
 		intel_dp->use_rate_select = true;
 	else
 		intel_dp_set_sink_rates(intel_dp);
+
+	intel_edp_set_data_override_rates(intel_dp);
 }
 
 static bool