drm: prune modes when output is disconnected.

When an output was disconnected, its mode list would remain.  If you later
plugged into a sink with no EDID (projector, etc), you'd inherit the mode
list from the old sink, which is not what you want.

taken from Fedora kernel

Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index c9a50c7..ff447f1 100644 (file)
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -95,8 +95,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
        if (connector->status == connector_status_disconnected) {
                DRM_DEBUG_KMS("%s is disconnected\n",
                          drm_get_connector_name(connector));
-               /* TODO set EDID to NULL */
-               return 0;
+               goto prune;
        }
 
        count = (*connector_funcs->get_modes)(connector);
@@ -124,6 +123,7 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
                                                                   mode);
        }
 
+prune:
        drm_mode_prune_invalid(dev, &connector->modes, true);
 
        if (list_empty(&connector->modes))