From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 4 Aug 2010 14:18:12 +0000 (+0100)
Subject: drm/i915: Unroll wrapping of the ringbuffer.
X-Git-Tag: v2.6.36-rc2~2^2~41
X-Git-Url: https://bbs.cooldavid.org/git/?a=commitdiff_plain;h=1741dd4aa7552055659bf74ab829a21579407f10;p=net-next-2.6.git

drm/i915: Unroll wrapping of the ringbuffer.

The tail is quadword aligned, so we can add two MI_NOOP as a time.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
---

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 26362f8495a..df8302a11eb 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -682,9 +682,11 @@ int intel_wrap_ring_buffer(struct drm_device *dev,
 	}
 
 	virt = (unsigned int *)(ring->virtual_start + ring->tail);
-	rem /= 4;
-	while (rem--)
+	rem /= 8;
+	while (rem--) {
 		*virt++ = MI_NOOP;
+		*virt++ = MI_NOOP;
+	}
 
 	ring->tail = 0;
 	ring->space = ring->head - 8;