@@ -480,10 +480,14 @@ static bool stop_ring(struct intel_engine_cs *engine)
}
}
- I915_WRITE_CTL(engine, 0);
+ I915_WRITE_HEAD(engine, I915_READ_TAIL(engine));
+
I915_WRITE_HEAD(engine, 0);
I915_WRITE_TAIL(engine, 0);
+ /* The ring must be empty before it is disabled */
+ I915_WRITE_CTL(engine, 0);
+
return (I915_READ_HEAD(engine) & HEAD_ADDR) == 0;
}
@@ -1387,10 +1387,14 @@ static void gen3_stop_engine(struct intel_engine_cs *engine)
DRM_DEBUG_DRIVER("%s: timed out on STOP_RING\n",
engine->name);
- I915_WRITE_FW(RING_CTL(base), 0);
+ I915_WRITE_FW(RING_HEAD(base), I915_READ_FW(RING_TAIL(base)));
+
I915_WRITE_FW(RING_HEAD(base), 0);
I915_WRITE_FW(RING_TAIL(base), 0);
+ /* The ring must be empty before it is disabled */
+ I915_WRITE_FW(RING_CTL(base), 0);
+
/* Check acts as a post */
if (I915_READ_FW(RING_HEAD(base)) != 0)
DRM_DEBUG_DRIVER("%s: ring head not parked\n",