RING_FAULT_REG
fault = I915_READ(RING_FAULT_REG(engine));
ee->fault_reg = I915_READ(RING_FAULT_REG(engine));
I915_WRITE(RING_FAULT_REG(engine),
I915_READ(RING_FAULT_REG(engine)) &
POSTING_READ(RING_FAULT_REG(dev_priv->engine[RCS]));