From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 6 Dec 2010 14:36:02 +0000 (+0000)
Subject: drm/i915: Only emit a flush if there is an outstanding gpu write
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=0ac74c6b3386f0413baf48f6d61850650e0dc4ab;p=deliverable%2Flinux.git

drm/i915: Only emit a flush if there is an outstanding gpu write

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8685b9279029..e7733333767d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2154,8 +2154,9 @@ static int i915_ring_idle(struct drm_device *dev,
 	if (list_empty(&ring->gpu_write_list) && list_empty(&ring->active_list))
 		return 0;
 
-	i915_gem_flush_ring(dev, ring,
-			    I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
+	if (!list_empty(&ring->gpu_write_list))
+		i915_gem_flush_ring(dev, ring,
+				    I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
 	return i915_wait_request(dev,
 				 i915_gem_next_request_seqno(dev, ring),
 				 ring);