drm/i915: Report the origin of the LVDS fixed panel mode

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
[danvet: resolve conflict around the call to intel_crtc_mode_get. And
add the missing NULL check Chris spotted while at it.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 2e26627..81502e8 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -1056,14 +1056,23 @@ bool intel_lvds_init(struct drm_device *dev)
 
        list_for_each_entry(scan, &connector->probed_modes, head) {
                if (scan->type & DRM_MODE_TYPE_PREFERRED) {
+                       DRM_DEBUG_KMS("using preferred mode from EDID: ");
+                       drm_mode_debug_printmodeline(scan);
+
                        fixed_mode = drm_mode_duplicate(dev, scan);
-                       intel_find_lvds_downclock(dev, fixed_mode, connector);
-                       goto out;
+                       if (fixed_mode) {
+                               intel_find_lvds_downclock(dev, fixed_mode,
+                                                         connector);
+                               goto out;
+                       }
                }
        }
 
        /* Failed to get EDID, what about VBT? */
        if (dev_priv->lfp_lvds_vbt_mode) {
+               DRM_DEBUG_KMS("using mode from VBT: ");
+               drm_mode_debug_printmodeline(dev_priv->lfp_lvds_vbt_mode);
+
                fixed_mode = drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode);
                if (fixed_mode) {
                        fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
@@ -1088,6 +1097,8 @@ bool intel_lvds_init(struct drm_device *dev)
        if (crtc && (lvds & LVDS_PORT_EN)) {
                fixed_mode = intel_crtc_mode_get(dev, crtc);
                if (fixed_mode) {
+                       DRM_DEBUG_KMS("using current (BIOS) mode: ");
+                       drm_mode_debug_printmodeline(fixed_mode);
                        fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
                        goto out;
                }