I915_READ_CTL
ee->ctl = I915_READ_CTL(engine);
if (I915_READ_CTL(signaller) & RING_WAIT_SEMAPHORE &&
tmp = I915_READ_CTL(engine);
I915_READ_CTL(engine),
I915_READ_CTL(engine),
I915_READ_CTL(engine),
I915_READ_CTL(engine) & RING_VALID,