drm/ttm: Allow execbuf util reserves without ticket

If no reservation ticket is given to the execbuf reservation utilities,
try reservation with non-blocking semantics.
This is intended for eviction paths that use the execbuf reservation
utilities for convenience rather than for deadlock avoidance.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/drm/ttm/ttm_execbuf_util.h b/include/drm/ttm/ttm_execbuf_util.h
index ec8a1d306510..16db7d01a336 100644
--- a/include/drm/ttm/ttm_execbuf_util.h
+++ b/include/drm/ttm/ttm_execbuf_util.h
@@ -70,7 +70,8 @@ extern void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
 /**
  * function ttm_eu_reserve_buffers
  *
- * @ticket:  [out] ww_acquire_ctx returned by call.
+ * @ticket:  [out] ww_acquire_ctx filled in by call, or NULL if only
+ *           non-blocking reserves should be tried.
  * @list:    thread private list of ttm_validate_buffer structs.
  *
  * Tries to reserve bos pointed to by the list entries for validation.