drm/i915/lvds: don't restore hw state in the lid notifier for pch platforms

[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / i915 / intel_lvds.c

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index c3b4da7895ed1c82b185b78ca06d00053cff2402..4c8553ea82f7f9f62c28fb7f3d2ca6f372e9fede 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -256,8 +256,9 @@ static void intel_disable_lvds(struct intel_encoder *encoder)
        POSTING_READ(lvds_encoder->reg);
 }
 
-static int intel_lvds_mode_valid(struct drm_connector *connector,
-                                struct drm_display_mode *mode)
+static enum drm_mode_status
+intel_lvds_mode_valid(struct drm_connector *connector,
+                     struct drm_display_mode *mode)
 {
        struct intel_connector *intel_connector = to_intel_connector(connector);
        struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
@@ -446,9 +447,19 @@ static int intel_lid_notify(struct notifier_block *nb, unsigned long val,
        if (dev_priv->modeset_restore == MODESET_DONE)
                goto exit;
 
-       drm_modeset_lock_all(dev);
-       intel_modeset_setup_hw_state(dev, true);
-       drm_modeset_unlock_all(dev);
+       /*
+        * Some old platform's BIOS love to wreak havoc while the lid is closed.
+        * We try to detect this here and undo any damage. The split for PCH
+        * platforms is rather conservative and a bit arbitrary expect that on
+        * those platforms VGA disabling requires actual legacy VGA I/O access,
+        * and as part of the cleanup in the hw state restore we also redisable
+        * the vga plane.
+        */
+       if (!HAS_PCH_SPLIT(dev)) {
+               drm_modeset_lock_all(dev);
+               intel_modeset_setup_hw_state(dev, true);
+               drm_modeset_unlock_all(dev);
+       }
 
        dev_priv->modeset_restore = MODESET_DONE;