[Intel-gfx] [PATCH 3/9] drm/i915: Only use VBT panel mode on eDP if no EDID is found

[Keith Packard]

We're going to assume that EDID is more reliable than the VBT tables
for eDP panels, which is notably true on MacBook machines where the
VBT contains completely bogus data.

Signed-off-by: Keith Packard <keithp at keithp.com>
---
 drivers/gpu/drm/i915/intel_dp.c |   20 ++++++++++----------
 1 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f0cfb6b..8ab2a88 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1748,7 +1748,16 @@ static int intel_dp_get_modes(struct drm_connector *connector)
 
 	/* if eDP has no EDID, try to use fixed panel mode from VBT */
 	if (is_edp(intel_dp)) {
-		if (dev_priv->panel_fixed_mode != NULL) {
+		/* initialize panel mode from VBT if available for eDP */
+		if (dev_priv->panel_fixed_mode == NULL && dev_priv->lfp_lvds_vbt_mode != NULL) {
+			dev_priv->panel_fixed_mode =
+				drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode);
+			if (dev_priv->panel_fixed_mode) {
+				dev_priv->panel_fixed_mode->type |=
+					DRM_MODE_TYPE_PREFERRED;
+			}
+		}
+		if (dev_priv->panel_fixed_mode) {
 			struct drm_display_mode *mode;
 			mode = drm_mode_duplicate(dev, dev_priv->panel_fixed_mode);
 			drm_mode_probed_add(connector, mode);
@@ -2061,15 +2070,6 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 	intel_encoder->hot_plug = intel_dp_hot_plug;
 
 	if (is_edp(intel_dp)) {
-		/* initialize panel mode from VBT if available for eDP */
-		if (dev_priv->lfp_lvds_vbt_mode) {
-			dev_priv->panel_fixed_mode =
-				drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode);
-			if (dev_priv->panel_fixed_mode) {
-				dev_priv->panel_fixed_mode->type |=
-					DRM_MODE_TYPE_PREFERRED;
-			}
-		}
 		dev_priv->int_edp_connector = connector;
 		intel_panel_setup_backlight(dev);
 	}
-- 
1.7.6.3