drm/nouveau/gem: fix fence_sync race / oops

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

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 5f0bc57..7ce3fde 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -379,6 +379,25 @@ retry:
        return 0;
 }
 
+static int
+validate_sync(struct nouveau_channel *chan, struct nouveau_bo *nvbo)
+{
+       struct nouveau_fence *fence = NULL;
+       int ret = 0;
+
+       spin_lock(&nvbo->bo.bdev->fence_lock);
+       if (nvbo->bo.sync_obj)
+               fence = nouveau_fence_ref(nvbo->bo.sync_obj);
+       spin_unlock(&nvbo->bo.bdev->fence_lock);
+
+       if (fence) {
+               ret = nouveau_fence_sync(fence, chan);
+               nouveau_fence_unref(&fence);
+       }
+
+       return ret;
+}
+
 static int
 validate_list(struct nouveau_channel *chan, struct list_head *list,
              struct drm_nouveau_gem_pushbuf_bo *pbbo, uint64_t user_pbbo_ptr)
@@ -393,7 +412,7 @@ validate_list(struct nouveau_channel *chan, struct list_head *list,
        list_for_each_entry(nvbo, list, entry) {
                struct drm_nouveau_gem_pushbuf_bo *b = &pbbo[nvbo->pbbo_index];
 
-               ret = nouveau_fence_sync(nvbo->bo.sync_obj, chan);
+               ret = validate_sync(chan, nvbo);
                if (unlikely(ret)) {
                        NV_ERROR(dev, "fail pre-validate sync\n");
                        return ret;
@@ -416,7 +435,7 @@ validate_list(struct nouveau_channel *chan, struct list_head *list,
                        return ret;
                }
 
-               ret = nouveau_fence_sync(nvbo->bo.sync_obj, chan);
+               ret = validate_sync(chan, nvbo);
                if (unlikely(ret)) {
                        NV_ERROR(dev, "fail post-validate sync\n");
                        return ret;