From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 8 Nov 2011 23:17:34 +0000 (+0000)
Subject: drm/i915:: Disable FBC on SandyBridge
X-Git-Tag: v3.2.20~24
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7a735af2d50190b6c612509c6dcad1b5aa0be828;p=thirdparty%2Fkernel%2Fstable.git

drm/i915:: Disable FBC on SandyBridge

commit d56d8b28e9247e7e35e02fbb12b12239a2c33ad1 upstream.

Enabling FBC is causing the BLT ring to run between 10-100x slower than
normal and frequently lockup. The interim solution is disable FBC once
more until we know why.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 41bbe78bb59c0..472039769dd64 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1864,7 +1864,7 @@ static void intel_update_fbc(struct drm_device *dev)
 	if (enable_fbc < 0) {
 		DRM_DEBUG_KMS("fbc set to per-chip default\n");
 		enable_fbc = 1;
-		if (INTEL_INFO(dev)->gen <= 5)
+		if (INTEL_INFO(dev)->gen <= 6)
 			enable_fbc = 0;
 	}
 	if (!enable_fbc) {