drm/i915/ehl: Ensure that the DDI selection MUX is programmed correctly

Perhaps in some cases the BIOS/GOP or other firmware may turn on
PHY A but may not program the MUX correctly. Therefore, re-program
PHY A if it is determined after reading the VBT that the value
programmed for the MUX bit does not match the expected value.

Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200121235848.8457-1-vivek.kasireddy@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_combo_phy.c b/drivers/gpu/drm/i915/display/intel_combo_phy.c
index 5f54aca7c36f8645dc05ed08d44c54a8f9060594..ec63c26579236a9b4339157a2f1509fee19236a8 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_combo_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_combo_phy.c
@@ -191,20 +191,57 @@ static bool icl_combo_phy_enabled(struct drm_i915_private *dev_priv,
                        (I915_READ(ICL_PORT_COMP_DW0(phy)) & COMP_INIT);
 }
 
+static bool ehl_vbt_ddi_d_present(struct drm_i915_private *i915)
+{
+       bool ddi_a_present = intel_bios_is_port_present(i915, PORT_A);
+       bool ddi_d_present = intel_bios_is_port_present(i915, PORT_D);
+       bool dsi_present = intel_bios_is_dsi_present(i915, NULL);
+
+       /*
+        * VBT's 'dvo port' field for child devices references the DDI, not
+        * the PHY.  So if combo PHY A is wired up to drive an external
+        * display, we should see a child device present on PORT_D and
+        * nothing on PORT_A and no DSI.
+        */
+       if (ddi_d_present && !ddi_a_present && !dsi_present)
+               return true;
+
+       /*
+        * If we encounter a VBT that claims to have an external display on
+        * DDI-D _and_ an internal display on DDI-A/DSI leave an error message
+        * in the log and let the internal display win.
+        */
+       if (ddi_d_present)
+               DRM_ERROR("VBT claims to have both internal and external displays on PHY A.  Configuring for internal.\n");
+
+       return false;
+}
+
 static bool icl_combo_phy_verify_state(struct drm_i915_private *dev_priv,
                                       enum phy phy)
 {
        bool ret;
+       u32 expected_val = 0;
 
        if (!icl_combo_phy_enabled(dev_priv, phy))
                return false;
 
        ret = cnl_verify_procmon_ref_values(dev_priv, phy);
 
-       if (phy == PHY_A)
+       if (phy == PHY_A) {
                ret &= check_phy_reg(dev_priv, phy, ICL_PORT_COMP_DW8(phy),
                                     IREFGEN, IREFGEN);
 
+               if (IS_ELKHARTLAKE(dev_priv)) {
+                       if (ehl_vbt_ddi_d_present(dev_priv))
+                               expected_val = ICL_PHY_MISC_MUX_DDID;
+
+                       ret &= check_phy_reg(dev_priv, phy, ICL_PHY_MISC(phy),
+                                            ICL_PHY_MISC_MUX_DDID,
+                                            expected_val);
+               }
+       }
+
        ret &= check_phy_reg(dev_priv, phy, ICL_PORT_CL_DW5(phy),
                             CL_POWER_DOWN_ENABLE, CL_POWER_DOWN_ENABLE);
 
@@ -263,32 +300,6 @@ void intel_combo_phy_power_up_lanes(struct drm_i915_private *dev_priv,
        I915_WRITE(ICL_PORT_CL_DW10(phy), val);
 }
 
-static u32 ehl_combo_phy_a_mux(struct drm_i915_private *i915, u32 val)
-{
-       bool ddi_a_present = intel_bios_is_port_present(i915, PORT_A);
-       bool ddi_d_present = intel_bios_is_port_present(i915, PORT_D);
-       bool dsi_present = intel_bios_is_dsi_present(i915, NULL);
-
-       /*
-        * VBT's 'dvo port' field for child devices references the DDI, not
-        * the PHY.  So if combo PHY A is wired up to drive an external
-        * display, we should see a child device present on PORT_D and
-        * nothing on PORT_A and no DSI.
-        */
-       if (ddi_d_present && !ddi_a_present && !dsi_present)
-               return val | ICL_PHY_MISC_MUX_DDID;
-
-       /*
-        * If we encounter a VBT that claims to have an external display on
-        * DDI-D _and_ an internal display on DDI-A/DSI leave an error message
-        * in the log and let the internal display win.
-        */
-       if (ddi_d_present)
-               DRM_ERROR("VBT claims to have both internal and external displays on PHY A.  Configuring for internal.\n");
-
-       return val & ~ICL_PHY_MISC_MUX_DDID;
-}
-
 static void icl_combo_phys_init(struct drm_i915_private *dev_priv)
 {
        enum phy phy;
@@ -319,8 +330,13 @@ static void icl_combo_phys_init(struct drm_i915_private *dev_priv)
                 * "internal" child devices.
                 */
                val = I915_READ(ICL_PHY_MISC(phy));
-               if (IS_ELKHARTLAKE(dev_priv) && phy == PHY_A)
-                       val = ehl_combo_phy_a_mux(dev_priv, val);
+               if (IS_ELKHARTLAKE(dev_priv) && phy == PHY_A) {
+                       val &= ~ICL_PHY_MISC_MUX_DDID;
+
+                       if (ehl_vbt_ddi_d_present(dev_priv))
+                               val |= ICL_PHY_MISC_MUX_DDID;
+               }
+
                val &= ~ICL_PHY_MISC_DE_IO_COMP_PWR_DOWN;
                I915_WRITE(ICL_PHY_MISC(phy), val);