drm/i915: Include RING_MODE when dumping the engine state

Knowing the RING_MODE flags is useful for checking the state of the
engine, such as whether the CS is idle after trying to stop the engines
before reset.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171026115048.20144-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>

drivers/gpu/drm/i915/intel_engine_cs.c

@@ -1723,9 +1723,14 @@ void intel_engine_dump(struct intel_engine_cs *engine, struct drm_printer *m)
 	drm_printf(m, "\tRING_TAIL:  0x%08x [0x%08x]\n",
 		   I915_READ(RING_TAIL(engine->mmio_base)) & TAIL_ADDR,
 		   rq ? rq->ring->tail : 0);
-	drm_printf(m, "\tRING_CTL:   0x%08x [%s]\n",
+	drm_printf(m, "\tRING_CTL:   0x%08x%s\n",
 		   I915_READ(RING_CTL(engine->mmio_base)),
-		   I915_READ(RING_CTL(engine->mmio_base)) & (RING_WAIT | RING_WAIT_SEMAPHORE) ? "waiting" : "");
+		   I915_READ(RING_CTL(engine->mmio_base)) & (RING_WAIT | RING_WAIT_SEMAPHORE) ? " [waiting]" : "");
+	if (INTEL_GEN(engine->i915) > 2) {
+		drm_printf(m, "\tRING_MODE:  0x%08x%s\n",
+			   I915_READ(RING_MI_MODE(engine->mmio_base)),
+			   I915_READ(RING_MI_MODE(engine->mmio_base)) & (MODE_IDLE) ? " [idle]" : "");
+	}
 
 	rcu_read_unlock();