@@ -913,6 +913,44 @@ static int intel_lid_present(void)
}
#endif
+
+/*
+ * Enumerate the child dev array parsed from VBT to check whether
+ * the LVDS is present.
+ * If it is present, return 1.
+ * If it is not present, return false.
+ * If no child dev is parsed from VBT, it assumes that the LVDS is present.
+ * Note: The addin_offset should also be checked for LVDS panel.
+ * Only when it is non-zero, it is assumed that it is present.
+ */
+int lvds_is_present_in_vbt(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct child_device_config *p_child;
+ int i, ret;
+
+ if (!dev_priv->child_dev_num)
+ return 1;
+
+ ret = 0;
+ for (i = 0; i < dev_priv->child_dev_num; i++) {
+ p_child = dev_priv->child_dev + i;
+ /*
+ * If the device type is not LFP, continue.
+ */
+ if (p_child->device_type != INT_LFP_CLASS)
+ continue;
+ /* The addin_offset should be checked. Only when it is
+ * non-zero, it is regarded as present.
+ */
+ if (p_child->addin_offset) {
+ ret = 1;
+ break;
+ }
+ }
+ return ret;
+}
+
/**
* intel_lvds_init - setup LVDS connectors on this device
* @dev: drm device
@@ -936,6 +974,10 @@ void intel_lvds_init(struct drm_device *dev)
if (dmi_check_system(intel_no_lvds))
return;
+ if (!lvds_is_present_in_vbt(dev)) {
+ DRM_DEBUG_KMS("LVDS is not present in VBT\n");
+ return;
+ }
/* Assume that any device without an ACPI LID device also doesn't
* have an integrated LVDS. We would be better off parsing the BIOS
* to get a reliable indicator, but that code isn't written yet.