[bug report] drm/ttm: switch to per device LRU lock

Hello Christian König,

This is a semi-automatic email about new static checker warnings.

The patch a1f091f8ef2b: "drm/ttm: switch to per device LRU lock" from Oct 6, 2020, leads to the following Smatch complaint:

drivers/gpu/drm/ttm/ttm_bo.c:665 ttm_mem_evict_first() error: we previously assumed 'bo' could be null (see line 662)

drivers/gpu/drm/ttm/ttm_bo.c 661 662 if (!bo) { ^^ "bo" is NULL

663 if (busy_bo && !ttm_bo_get_unless_zero(busy_bo)) 664 busy_bo = NULL; 665 spin_unlock(&bo->bdev->lru_lock); ^^^^^^^^^^^^^^^^^^ Dereference

666 ret = ttm_mem_evict_wait_busy(busy_bo, ctx, ticket); 667 if (busy_bo)

regards, dan carpenter