drm/i915: Fix LVDS presence check

Combined patches from 2.6.33 for fixing LVDS detection.
7cf4f69d
    drm/i915: Don't set up the LVDS if it isn't in the BIOS device table.
38b3037e
    drm/i915: Fix LVDS presence check
6e36595a
    drm/i915: Declare the new VBT parsing functions as static
11ba1592
    drm/i915: Don't check for lid presence when detecting LVDS
Acked-by: Takashi Iwai <tiwai@suse.de>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Adam Jackson <ajax@redhat.com>
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/gpu/drm/i915/intel_lvds.c

@@ -901,64 +901,45 @@ static const struct dmi_system_id intel_no_lvds[] = {
 	{ }	/* terminating entry */
 };
 
-#ifdef CONFIG_ACPI
 /*
- * check_lid_device -- check whether @handle is an ACPI LID device.
- * @handle: ACPI device handle
- * @level : depth in the ACPI namespace tree
- * @context: the number of LID device when we find the device
- * @rv: a return value to fill if desired (Not use)
+ * 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.
  */
-static acpi_status
-check_lid_device(acpi_handle handle, u32 level, void *context,
-			void **return_value)
+static int lvds_is_present_in_vbt(struct drm_device *dev)
 {
-	struct acpi_device *acpi_dev;
-	int *lid_present = context;
-
-	acpi_dev = NULL;
-	/* Get the acpi device for device handle */
-	if (acpi_bus_get_device(handle, &acpi_dev) || !acpi_dev) {
-		/* If there is no ACPI device for handle, return */
-		return AE_OK;
-	}
-
-	if (!strncmp(acpi_device_hid(acpi_dev), "PNP0C0D", 7))
-		*lid_present = 1;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct child_device_config *p_child;
+	int i, ret;
 
-	return AE_OK;
-}
+	if (!dev_priv->child_dev_num)
+		return 1;
 
-/**
- * check whether there exists the ACPI LID device by enumerating the ACPI
- * device tree.
- */
-static int intel_lid_present(void)
-{
-	int lid_present = 0;
+	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 the device type is 0x22, it is also regarded as LFP.
+		 */
+		if (p_child->device_type != DEVICE_TYPE_INT_LFP &&
+			p_child->device_type != DEVICE_TYPE_LFP)
+			continue;
 
-	if (acpi_disabled) {
-		/* If ACPI is disabled, there is no ACPI device tree to
-		 * check, so assume the LID device would have been present.
+		/* The addin_offset should be checked. Only when it is
+		 * non-zero, it is regarded as present.
 		 */
-		return 1;
+		if (p_child->addin_offset) {
+			ret = 1;
+			break;
+		}
 	}
-
-	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
-				ACPI_UINT32_MAX,
-				check_lid_device, &lid_present, NULL);
-
-	return lid_present;
-}
-#else
-static int intel_lid_present(void)
-{
-	/* In the absence of ACPI built in, assume that the LID device would
-	 * have been present.
-	 */
-	return 1;
+	return ret;
 }
-#endif
 
 /**
  * intel_lvds_init - setup LVDS connectors on this device
@@ -983,15 +964,10 @@ void intel_lvds_init(struct drm_device *dev)
 	if (dmi_check_system(intel_no_lvds))
 		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.
-	 *
-	 * In the case of all-in-one desktops using LVDS that we've seen,
-	 * they're using SDVO LVDS.
-	 */
-	if (!intel_lid_present())
+	if (!lvds_is_present_in_vbt(dev)) {
+		DRM_DEBUG_KMS("LVDS is not present in VBT\n");
 		return;
+	}
 
 	if (IS_IGDNG(dev)) {
 		if ((I915_READ(PCH_LVDS) & LVDS_DETECTED) == 0)