drm/i915: Fix platform default aux ch for skl

SKL/derivatives have DDI E but no AUX E, so we need to pick
another aux ch as the platform default. DDI E is more or less
the other half of DDI A, so we pick AUX A.

In all other cases we should have a corresponding aux ch for
each DDI.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230216231312.32664-3-ville.syrjala@linux.intel.com
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
index 57eb3ff187fa9cbe19f0ff27111cd4065f49b144..96967e21c94c2c9c813d81273fdfad9613eb653f 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
@@ -739,10 +739,20 @@ void intel_dp_aux_init(struct intel_dp *intel_dp)
        cpu_latency_qos_add_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);
 }
 
+static enum aux_ch default_aux_ch(struct intel_encoder *encoder)
+{
+       struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+
+       /* SKL has DDI E but no AUX E */
+       if (DISPLAY_VER(i915) == 9 && encoder->port == PORT_E)
+               return AUX_CH_A;
+
+       return (enum aux_ch)encoder->port;
+}
+
 enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder)
 {
        struct drm_i915_private *i915 = to_i915(encoder->base.dev);
-       enum port port = encoder->port;
        enum aux_ch aux_ch;
 
        aux_ch = intel_bios_dp_aux_ch(encoder->devdata);
@@ -753,7 +763,7 @@ enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder)
                return aux_ch;
        }
 
-       aux_ch = (enum aux_ch)port;
+       aux_ch = default_aux_ch(encoder);
 
        drm_dbg_kms(&i915->drm,
                    "[ENCODER:%d:%s] using AUX %c (platform default)\n",