drm/i915: Reduce breadcrumb lock coverage for intel_engine_enable_signaling()

Since intel_engine_enable_signaling() is now only called via
fence_enable_sw_signaling(), we can rely on it to provide serialisation
and run-once for us and so make ourselves slightly simpler.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-2-git-send-email-chris@chris-wilson.co.uk
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469530913-17180-1-git-send-email-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2016-07-26 12:01:50 +01:00
parent d2b9448f96
commit 4a50d20e10

View file

@ -480,19 +480,15 @@ void intel_engine_enable_signaling(struct drm_i915_gem_request *request)
struct rb_node *parent, **p;
bool first, wakeup;
if (unlikely(READ_ONCE(request->signaling.wait.tsk)))
return;
spin_lock(&b->lock);
if (unlikely(request->signaling.wait.tsk)) {
wakeup = false;
goto unlock;
}
/* locked by fence_enable_sw_signaling() */
assert_spin_locked(&request->lock);
request->signaling.wait.tsk = b->signaler;
request->signaling.wait.seqno = request->fence.seqno;
i915_gem_request_get(request);
spin_lock(&b->lock);
/* First add ourselves into the list of waiters, but register our
* bottom-half as the signaller thread. As per usual, only the oldest
* waiter (not just signaller) is tasked as the bottom-half waking
@ -525,7 +521,6 @@ void intel_engine_enable_signaling(struct drm_i915_gem_request *request)
if (first)
smp_store_mb(b->first_signal, request);
unlock:
spin_unlock(&b->lock);
if (wakeup)