drm/i915: Add *_ring_begin() to request allocation
Now that the *_ring_begin() functions no longer call the request allocation
code, it is finally safe for the request allocation code to call *_ring_begin().
This is important to guarantee that the space reserved for the subsequent
i915_add_request() call does actually get reserved.
v2: Renamed functions according to review feedback (Tomas Elf).
For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e7a40f8..0af4960 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2679,19 +2679,20 @@
* i915_add_request() call can't fail. Note that the reserve may need
* to be redone if the request is not actually submitted straight
* away, e.g. because a GPU scheduler has deferred it.
- *
- * Note further that this call merely notes the reserve request. A
- * subsequent call to *_ring_begin() is required to actually ensure
- * that the reservation is available. Without the begin, if the
- * request creator immediately submitted the request without adding
- * any commands to it then there might not actually be sufficient
- * room for the submission commands. Unfortunately, the current
- * *_ring_begin() implementations potentially call back here to
- * i915_gem_request_alloc(). Thus calling _begin() here would lead to
- * infinite recursion! Until that back call path is removed, it is
- * necessary to do a manual _begin() outside.
*/
- intel_ring_reserved_space_reserve(req->ringbuf, MIN_SPACE_FOR_ADD_REQUEST);
+ if (i915.enable_execlists)
+ ret = intel_logical_ring_reserve_space(req);
+ else
+ ret = intel_ring_reserve_space(req);
+ if (ret) {
+ /*
+ * At this point, the request is fully allocated even if not
+ * fully prepared. Thus it can be cleaned up using the proper
+ * free code.
+ */
+ i915_gem_request_cancel(req);
+ return ret;
+ }
*req_out = ring->outstanding_lazy_request = req;
return 0;