From 1b63cd0835e25cface2a859a5574aa9afab2300b Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 5 Jul 2012 23:49:40 +0100
Subject: [PATCH] --- yaml --- r: 318755 b: refs/heads/master c:
 67b1b57182972f3c89c1ff9a58951582cb6bcca7 h: refs/heads/master i:   318753:
 378da9c7a9d587acb0444ece1265ba4ab581fb65   318751:
 ee0e8790ca63580e67c89cd65b4baa0b907a13b7 v: v3

---
 [refs]                                |  2 +-
 trunk/drivers/gpu/drm/i915/i915_gem.c | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 883bbd33dca1..667228622fb6 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0232e927f8b0b37f5c82648f9bc45e55fb245068
+refs/heads/master: 67b1b57182972f3c89c1ff9a58951582cb6bcca7
diff --git a/trunk/drivers/gpu/drm/i915/i915_gem.c b/trunk/drivers/gpu/drm/i915/i915_gem.c
index 0fdb3d29cbbb..89d62f635ac8 100644
--- a/trunk/drivers/gpu/drm/i915/i915_gem.c
+++ b/trunk/drivers/gpu/drm/i915/i915_gem.c
@@ -3726,6 +3726,22 @@ void i915_gem_init_ppgtt(struct drm_device *dev)
 	}
 }
 
+static bool
+intel_enable_blt(struct drm_device *dev)
+{
+	if (!HAS_BLT(dev))
+		return false;
+
+	/* The blitter was dysfunctional on early prototypes */
+	if (IS_GEN6(dev) && dev->pdev->revision < 8) {
+		DRM_INFO("BLT not supported on this pre-production hardware;"
+			 " graphics performance will be degraded.\n");
+		return false;
+	}
+
+	return true;
+}
+
 int
 i915_gem_init_hw(struct drm_device *dev)
 {
@@ -3749,7 +3765,7 @@ i915_gem_init_hw(struct drm_device *dev)
 			goto cleanup_render_ring;
 	}
 
-	if (HAS_BLT(dev)) {
+	if (intel_enable_blt(dev)) {
 		ret = intel_init_blt_ring_buffer(dev);
 		if (ret)
 			goto cleanup_bsd_ring;