drm/i915: Fix LVDS presence check

Assume that either the presence of an LVDS entry in the VBT or an ACPI
lid device indicates an LVDS device.  ACPI lid alone is not sufficient.
Signed-off-by: NAdam Jackson <ajax@redhat.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/intel_lvds.c

@@ -1031,19 +1031,14 @@ 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.
-	 *
-	 * In the case of all-in-one desktops using LVDS that we've seen,
-	 * they're using SDVO LVDS.
+	/*
+	 * Assume LVDS is present if there's an ACPI lid device or if the
+	 * device is present in the VBT.
 	 */
-	if (!intel_lid_present())
+	if (!lvds_is_present_in_vbt(dev) && !intel_lid_present()) {
+		DRM_DEBUG_KMS("LVDS is not present in VBT and no lid detected\n");
 		return;
+	}
 
 	if (IS_IGDNG(dev)) {
 		if ((I915_READ(PCH_LVDS) & LVDS_DETECTED) == 0)