drm/i915: Return SDVO LVDS VBT mode if no EDID modes are detected.

Some new SDVO LVDS hardware doesn't have DDC available, and this should
fix the display on it.

Signed-off-by: Ma Ling <ling.ma@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 9913651c1e1703d78dba7eb34ab3fdd82135a3e3..f79ebf4de63cdebea53c6331f13c25e110798d2f 100644 (file)
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -69,6 +69,10 @@ struct intel_sdvo_priv {
         * This is set if we treat the device as HDMI, instead of DVI.
         */
        bool is_hdmi;
+       /**
+        * This is set if we detect output of sdvo device as LVDS.
+        */
+       bool is_lvds;
 
        /**
         * Returned SDTV resolutions allowed for the current format, if the
@@ -1543,6 +1547,37 @@ static void intel_sdvo_get_tv_modes(struct drm_connector *connector)
                }
 }
 
+static void intel_sdvo_get_lvds_modes(struct drm_connector *connector)
+{
+       struct intel_output *intel_output = to_intel_output(connector);
+       struct intel_sdvo_priv *sdvo_priv = intel_output->dev_priv;
+       struct drm_i915_private *dev_priv = connector->dev->dev_private;
+
+       /*
+        * Attempt to get the mode list from DDC.
+        * Assume that the preferred modes are
+        * arranged in priority order.
+        */
+       /* set the bus switch and get the modes */
+       intel_sdvo_set_control_bus_switch(intel_output, sdvo_priv->ddc_bus);
+       intel_ddc_get_modes(intel_output);
+       if (list_empty(&connector->probed_modes) == false)
+               return;
+
+       /* Fetch modes from VBT */
+       if (dev_priv->sdvo_lvds_vbt_mode != NULL) {
+               struct drm_display_mode *newmode;
+               newmode = drm_mode_duplicate(connector->dev,
+                                            dev_priv->sdvo_lvds_vbt_mode);
+               if (newmode != NULL) {
+                       /* Guarantee the mode is preferred */
+                       newmode->type = (DRM_MODE_TYPE_PREFERRED |
+                                        DRM_MODE_TYPE_DRIVER);
+                       drm_mode_probed_add(connector, newmode);
+               }
+       }
+}
+
 static int intel_sdvo_get_modes(struct drm_connector *connector)
 {
        struct intel_output *output = to_intel_output(connector);
@@ -1550,6 +1585,8 @@ static int intel_sdvo_get_modes(struct drm_connector *connector)
 
        if (sdvo_priv->is_tv)
                intel_sdvo_get_tv_modes(connector);
+       else if (sdvo_priv->is_lvds == true)
+               intel_sdvo_get_lvds_modes(connector);
        else
                intel_sdvo_get_ddc_modes(connector);
 
@@ -1720,6 +1757,8 @@ bool intel_sdvo_init(struct drm_device *dev, int output_device)
                }
        }
 
+       /* In defaut case sdvo lvds is false */
+       sdvo_priv->is_lvds = false;
        intel_sdvo_get_capabilities(intel_output, &sdvo_priv->caps);
 
        if (sdvo_priv->caps.output_flags &
@@ -1773,6 +1812,7 @@ bool intel_sdvo_init(struct drm_device *dev, int output_device)
                connector->display_info.subpixel_order = SubPixelHorizontalRGB;
                encoder_type = DRM_MODE_ENCODER_LVDS;
                connector_type = DRM_MODE_CONNECTOR_LVDS;
+               sdvo_priv->is_lvds = true;
        }
        else if (sdvo_priv->caps.output_flags & SDVO_OUTPUT_LVDS1)
        {
@@ -1780,6 +1820,7 @@ bool intel_sdvo_init(struct drm_device *dev, int output_device)
                connector->display_info.subpixel_order = SubPixelHorizontalRGB;
                encoder_type = DRM_MODE_ENCODER_LVDS;
                connector_type = DRM_MODE_CONNECTOR_LVDS;
+               sdvo_priv->is_lvds = true;
        }
        else
        {