drm/i915: Unwrap top level fence-array
By first unwrapping an incoming fence-array into its child fences, we
can simplify the internal branching, and so avoid triggering a potential
bug in the next patch when not squashing the child fences on the same
timeline.
It will also have the advantage of keeping the (top-level) fence arrays
out of any fence/timeline caching since these are unordered timelines
but with a random context id.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170503093924.5320-2-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 6198f69..b68935d 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -743,22 +743,9 @@ int
i915_gem_request_await_dma_fence(struct drm_i915_gem_request *req,
struct dma_fence *fence)
{
- struct dma_fence_array *array;
+ struct dma_fence **child = &fence;
+ unsigned int nchild = 1;
int ret;
- int i;
-
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
- return 0;
-
- if (dma_fence_is_i915(fence))
- return i915_gem_request_await_request(req, to_request(fence));
-
- if (!dma_fence_is_array(fence)) {
- ret = i915_sw_fence_await_dma_fence(&req->submit,
- fence, I915_FENCE_TIMEOUT,
- GFP_KERNEL);
- return ret < 0 ? ret : 0;
- }
/* Note that if the fence-array was created in signal-on-any mode,
* we should *not* decompose it into its individual fences. However,
@@ -767,21 +754,29 @@ i915_gem_request_await_dma_fence(struct drm_i915_gem_request *req,
* amdgpu and we should not see any incoming fence-array from
* sync-file being in signal-on-any mode.
*/
+ if (dma_fence_is_array(fence)) {
+ struct dma_fence_array *array = to_dma_fence_array(fence);
- array = to_dma_fence_array(fence);
- for (i = 0; i < array->num_fences; i++) {
- struct dma_fence *child = array->fences[i];
+ child = array->fences;
+ nchild = array->num_fences;
+ GEM_BUG_ON(!nchild);
+ }
- if (dma_fence_is_i915(child))
+ do {
+ fence = *child++;
+ if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+ continue;
+
+ if (dma_fence_is_i915(fence))
ret = i915_gem_request_await_request(req,
- to_request(child));
+ to_request(fence));
else
- ret = i915_sw_fence_await_dma_fence(&req->submit,
- child, I915_FENCE_TIMEOUT,
+ ret = i915_sw_fence_await_dma_fence(&req->submit, fence,
+ I915_FENCE_TIMEOUT,
GFP_KERNEL);
if (ret < 0)
return ret;
- }
+ } while (--nchild);
return 0;
}