drm/i915: Disable LVDS port after the pipe on PCH

Follow the correct pipe vs port disable sequence for the PCH LVDS
ports, ie. disable the port after the pipe.

Other PCH port were already converted in the following commits:
 1ea56e26 drm/i915: Disable CRT port after pipe on PCH platforms
 3c65d1d1 drm/i915: Disable SDVO port after the pipe on PCH platforms
 a4790cec drm/i915: Disable HDMI port after the pipe on PCH platforms
 08aff3fe drm/i915: Move DP port disable to post_disable for pch platforms
but LVDS was forgotten.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_lvds.c

@@ -239,8 +239,6 @@ static void intel_disable_lvds(struct intel_encoder *encoder)
 {
 	struct drm_device *dev = encoder->base.dev;
 	struct intel_lvds_encoder *lvds_encoder = to_lvds_encoder(&encoder->base);
-	struct intel_connector *intel_connector =
-		&lvds_encoder->attached_connector->base;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32 ctl_reg, stat_reg;
 
@@ -252,8 +250,6 @@ static void intel_disable_lvds(struct intel_encoder *encoder)
 		stat_reg = PP_STATUS;
 	}
 
-	intel_panel_disable_backlight(intel_connector);
-
 	I915_WRITE(ctl_reg, I915_READ(ctl_reg) & ~POWER_TARGET_ON);
 	if (wait_for((I915_READ(stat_reg) & PP_ON) == 0, 1000))
 		DRM_ERROR("timed out waiting for panel to power off\n");
@@ -262,6 +258,31 @@ static void intel_disable_lvds(struct intel_encoder *encoder)
 	POSTING_READ(lvds_encoder->reg);
 }
 
+static void gmch_disable_lvds(struct intel_encoder *encoder)
+{
+	struct intel_lvds_encoder *lvds_encoder = to_lvds_encoder(&encoder->base);
+	struct intel_connector *intel_connector =
+		&lvds_encoder->attached_connector->base;
+
+	intel_panel_disable_backlight(intel_connector);
+
+	intel_disable_lvds(encoder);
+}
+
+static void pch_disable_lvds(struct intel_encoder *encoder)
+{
+	struct intel_lvds_encoder *lvds_encoder = to_lvds_encoder(&encoder->base);
+	struct intel_connector *intel_connector =
+		&lvds_encoder->attached_connector->base;
+
+	intel_panel_disable_backlight(intel_connector);
+}
+
+static void pch_post_disable_lvds(struct intel_encoder *encoder)
+{
+	intel_disable_lvds(encoder);
+}
+
 static enum drm_mode_status
 intel_lvds_mode_valid(struct drm_connector *connector,
 		      struct drm_display_mode *mode)
@@ -992,7 +1013,12 @@ void intel_lvds_init(struct drm_device *dev)
 	intel_encoder->enable = intel_enable_lvds;
 	intel_encoder->pre_enable = intel_pre_enable_lvds;
 	intel_encoder->compute_config = intel_lvds_compute_config;
-	intel_encoder->disable = intel_disable_lvds;
+	if (HAS_PCH_SPLIT(dev_priv)) {
+		intel_encoder->disable = pch_disable_lvds;
+		intel_encoder->post_disable = pch_post_disable_lvds;
+	} else {
+		intel_encoder->disable = gmch_disable_lvds;
+	}
 	intel_encoder->get_hw_state = intel_lvds_get_hw_state;
 	intel_encoder->get_config = intel_lvds_get_config;
 	intel_connector->get_hw_state = intel_connector_get_hw_state;