From: Jani Nikula <jani.nikula@xxxxxxxxx>
Combo phy is limited to 5.4 GHz on low-voltage SKUs. Combo phy DP is
limited to 5.4 GHz, while combo phy eDP can do 8.1 GHz.
Bspec: 20584, 20598, 49180, 49201
Cc: Imre Deak <imre.deak@xxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_dp.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 7e823c02c1e9..d7486017b7f6 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -291,6 +291,15 @@ static int dg2_max_source_rate(struct intel_dp *intel_dp)
return intel_dp_is_edp(intel_dp) ? 810000 : 1350000;
}
+static bool is_low_voltage_sku(struct drm_i915_private *i915, enum phy phy)
+{
+ u32 voltage;
+
+ voltage = intel_de_read(i915, ICL_PORT_COMP_DW3(phy)) & VOLTAGE_INFO_MASK;
+
+ return voltage == VOLTAGE_INFO_0_85V;
+}
+
static int icl_max_source_rate(struct intel_dp *intel_dp)
{
struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
@@ -298,7 +307,7 @@ static int icl_max_source_rate(struct intel_dp *intel_dp)
enum phy phy = intel_port_to_phy(dev_priv, dig_port->base.port);
if (intel_phy_is_combo(dev_priv, phy) &&
- !intel_dp_is_edp(intel_dp))
+ (is_low_voltage_sku(dev_priv, phy) || !intel_dp_is_edp(intel_dp)))
return 540000;
return 810000;
--
2.29.0
