drm: try to restore previous CRTC config if mode set fails
Jesse Barnes [Mon, 7 Nov 2011 18:39:57 +0000 (10:39 -0800)]
We restore the CRTC, encoder, and connector configurations, but if the
mode set failed, the attached display may have been turned off, so we
need to try set_config again to restore things to the way they were.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_crtc_helper.c

index 2957636..3969f75 100644 (file)
@@ -484,6 +484,7 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
        struct drm_connector *save_connectors, *connector;
        int count = 0, ro, fail = 0;
        struct drm_crtc_helper_funcs *crtc_funcs;
+       struct drm_mode_set save_set;
        int ret = 0;
        int i;
 
@@ -556,6 +557,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
                save_connectors[count++] = *connector;
        }
 
+       save_set.crtc = set->crtc;
+       save_set.mode = &set->crtc->mode;
+       save_set.x = set->crtc->x;
+       save_set.y = set->crtc->y;
+       save_set.fb = set->crtc->fb;
+
        /* We should be able to check here if the fb has the same properties
         * and then just flip_or_move it */
        if (set->crtc->fb != set->fb) {
@@ -721,6 +728,12 @@ fail:
                *connector = save_connectors[count++];
        }
 
+       /* Try to restore the config */
+       if (mode_changed &&
+           !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
+                                     save_set.y, save_set.fb))
+               DRM_ERROR("failed to restore config after modeset failure\n");
+
        kfree(save_connectors);
        kfree(save_encoders);
        kfree(save_crtcs);