drm/i915: Hold reference to previous active fence as we queue (30ca04e1) · Commits · 戴 / test

Take a reference to the previous exclusive fence on the i915_active, as we wish to add an await to it in the caller (and so must prevent it from being freed until we have completed that task). Fixes: ("drm/i915: Use the async worker to avoid reclaim tainting the ggtt->mutex") Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Matthew Auld <matthew.auld@intel.com> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200203094152.4150550-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_active.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -398,9 +398,13 @@ i915_active_set_exclusive(struct i915_active ref, struct dma_fence f)
		/* We expect the caller to manage the exclusive timeline ordering */
		GEM_BUG_ON(i915_active_is_idle(ref));

		rcu_read_lock();
		prev = __i915_active_fence_set(&ref->excl, f);
		if (!prev)
		if (prev)
		prev = dma_fence_get_rcu(prev);
		else
		atomic_inc(&ref->count);
		rcu_read_unlock();

		return prev;
		}

drivers/gpu/drm/i915/i915_vma.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -422,10 +422,12 @@ int i915_vma_bind(struct i915_vma *vma,
		* execution and not content or object's backing store lifetime.
		*/
		prev = i915_active_set_exclusive(&vma->active, &work->base.dma);
		if (prev)
		if (prev) {
		__i915_sw_fence_await_dma_fence(&work->base.chain,
		prev,
		&work->cb);
		dma_fence_put(prev);
		}

		work->base.dma.error = 0; /* enable the queue_work() */

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