drm/i915: Add fixed panel mode parsed from EDID for eDP without fixed mode in VBT

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f7410cffa8c9..2b99ab23dc8a 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1374,8 +1374,22 @@ static int intel_dp_get_modes(struct drm_connector *connector)
          */
 
         ret = intel_ddc_get_modes(connector, intel_encoder->ddc_bus);
-        if (ret)
+        if (ret) {
+                if ((IS_eDP(intel_encoder) || IS_PCH_eDP(dp_priv)) &&
+                    !dev_priv->panel_fixed_mode) {
+                        struct drm_display_mode *newmode;
+                        list_for_each_entry(newmode, &connector->probed_modes,
+                                            head) {
+                                if (newmode->type & DRM_MODE_TYPE_PREFERRED) {
+                                        dev_priv->panel_fixed_mode =
+                                                drm_mode_duplicate(dev, newmode);
+                                        break;
+                                }
+                        }
+                }
+
                 return ret;
+        }
 
         /* if eDP has no EDID, try to use fixed panel mode from VBT */
         if (IS_eDP(intel_encoder) || IS_PCH_eDP(dp_priv)) {