drm/kms: teardown crtc correctly when fb is destroyed.

If userspace destroys a framebuffer that is in use on a crtc,
don't just null it out, tear down the crtc properly so the
hw gets turned off.

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

1 files changed, 12 insertions, 28 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 33be210d6723..2f631c75f704 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -258,31 +258,6 @@ void *drm_mode_object_find(struct drm_device *dev, uint32_t id, uint32_t type)
 EXPORT_SYMBOL(drm_mode_object_find);
 
 /**
- * drm_crtc_from_fb - find the CRTC structure associated with an fb
- * @dev: DRM device
- * @fb: framebuffer in question
- *
- * LOCKING:
- * Caller must hold mode_config lock.
- *
- * Find CRTC in the mode_config structure that matches @fb.
- *
- * RETURNS:
- * Pointer to the CRTC or NULL if it wasn't found.
- */
-struct drm_crtc *drm_crtc_from_fb(struct drm_device *dev,
-                                  struct drm_framebuffer *fb)
-{
-        struct drm_crtc *crtc;
-
-        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-                if (crtc->fb == fb)
-                        return crtc;
-        }
-        return NULL;
-}
-
-/**
  * drm_framebuffer_init - initialize a framebuffer
  * @dev: DRM device
  *
@@ -328,11 +303,20 @@ void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
 {
         struct drm_device *dev = fb->dev;
         struct drm_crtc *crtc;
+        struct drm_mode_set set;
+        int ret;
 
         /* remove from any CRTC */
         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-                if (crtc->fb == fb)
-                        crtc->fb = NULL;
+                if (crtc->fb == fb) {
+                        /* should turn off the crtc */
+                        memset(&set, 0, sizeof(struct drm_mode_set));
+                        set.crtc = crtc;
+                        set.fb = NULL;
+                        ret = crtc->funcs->set_config(&set);
+                        if (ret)
+                                DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
+                }
         }
 
         drm_mode_object_put(dev, &fb->base);
@@ -1511,7 +1495,7 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
         set.mode = mode;
         set.connectors = connector_set;
         set.num_connectors = crtc_req->count_connectors;
-        set.fb =fb;
+        set.fb = fb;
         ret = crtc->funcs->set_config(&set);
 
 out: