drm/i915/dp: Fix eDP max rate for display 11+

intel_dp_set_source_rates() calls intel_dp_is_edp(), which is unsafe to
use before intel_encoder->type is set. This causes incorrect max source
rate to be used for display 11+. On EHL and JSL, HBR3 is used instead of
HBR2, and on the other affected platforms, HBR2 is used instead of HBR3.

Move intel_dp_set_source_rates() to after intel_encoder->type is
set. Add comment to intel_dp_is_edp() describing unsafe usages. Cleanup
intel_dp_init_connector() while at it.

Note: The same change was originally added as commit 680c45c767f6
("drm/i915/dp: Correctly advertise HBR3 for GEN11+"), but later reverted
due to issues in CI in commit d3913019602e ("Revert "drm/i915/dp:
Correctly advertise HBR3 for GEN11+"").

Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210901160402.24816-2-animesh.manna@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 81b7097..322ffe7 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -102,6 +102,8 @@ static const u8 valid_dsc_slicecount[] = {1, 2, 4};
  *
  * If a CPU or PCH DP output is attached to an eDP panel, this function
  * will return true, and false otherwise.
+ *
+ * This function is not safe to use prior to encoder type being set.
  */
 bool intel_dp_is_edp(struct intel_dp *intel_dp)
 {
@@ -4899,8 +4901,6 @@ intel_dp_init_connector(struct intel_digital_port *dig_port,
                     intel_encoder->base.name))
                return false;
 
-       intel_dp_set_source_rates(intel_dp);
-
        intel_dp->reset_link_params = true;
        intel_dp->pps.pps_pipe = INVALID_PIPE;
        intel_dp->pps.active_pipe = INVALID_PIPE;
@@ -4916,28 +4916,22 @@ intel_dp_init_connector(struct intel_digital_port *dig_port,
                 */
                drm_WARN_ON(dev, intel_phy_is_tc(dev_priv, phy));
                type = DRM_MODE_CONNECTOR_eDP;
+               intel_encoder->type = INTEL_OUTPUT_EDP;
+
+               /* eDP only on port B and/or C on vlv/chv */
+               if (drm_WARN_ON(dev, (IS_VALLEYVIEW(dev_priv) ||
+                                     IS_CHERRYVIEW(dev_priv)) &&
+                               port != PORT_B && port != PORT_C))
+                       return false;
        } else {
                type = DRM_MODE_CONNECTOR_DisplayPort;
        }
 
+       intel_dp_set_source_rates(intel_dp);
+
        if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                intel_dp->pps.active_pipe = vlv_active_pipe(intel_dp);
 
-       /*
-        * For eDP we always set the encoder type to INTEL_OUTPUT_EDP, but
-        * for DP the encoder type can be set by the caller to
-        * INTEL_OUTPUT_UNKNOWN for DDI, so don't rewrite it.
-        */
-       if (type == DRM_MODE_CONNECTOR_eDP)
-               intel_encoder->type = INTEL_OUTPUT_EDP;
-
-       /* eDP only on port B and/or C on vlv/chv */
-       if (drm_WARN_ON(dev, (IS_VALLEYVIEW(dev_priv) ||
-                             IS_CHERRYVIEW(dev_priv)) &&
-                       intel_dp_is_edp(intel_dp) &&
-                       port != PORT_B && port != PORT_C))
-               return false;
-
        drm_dbg_kms(&dev_priv->drm,
                    "Adding %s connector on [ENCODER:%d:%s]\n",
                    type == DRM_MODE_CONNECTOR_eDP ? "eDP" : "DP",