drm: try to restore previous CRTC config if mode set fails

[pandora-kernel.git] / drivers / gpu / drm / drm_crtc_helper.c

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index f236644..3969f75 100644 (file)
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -29,6 +29,9 @@
  *      Jesse Barnes <jesse.barnes@intel.com>
  */
 
+#include <linux/export.h>
+#include <linux/moduleparam.h>
+
 #include "drmP.h"
 #include "drm_crtc.h"
 #include "drm_crtc_helper.h"
@@ -481,6 +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;
 
@@ -553,6 +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) {
@@ -718,6 +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);