From 9169d3a88072b20f42e68a946e916bd7dfbc7f2c Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Wed, 10 Oct 2012 23:14:01 +0200
Subject: [PATCH] drm/i915: disable wc gtt pte mappings on gen2
It doesn't work since the gtt pte range sits in the middle of the mmio
bar. We didn't notice that since both my and Chris' gen2 machines
don't support PAT and hence all wc io mapping request will
automatically be demoted to uc.
This regression has been introduce in
commit edef7e685da05c13cce50c0126189c80fe2c8f71
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri Sep 14 11:57:47 2012 +0100
agp/intel: Use a write-combining map for updating PTEs
Reported-by: Egbert Eich <eich@pdx.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=55834
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
drivers/char/agp/intel-gtt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index e01f5eaaec82..38390f7c6ab6 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -667,7 +667,7 @@ static int intel_gtt_init(void)
gtt_map_size = intel_private.base.gtt_total_entries * 4;
intel_private.gtt = NULL;
- if (INTEL_GTT_GEN < 6)
+ if (INTEL_GTT_GEN < 6 && INTEL_GTT_GEN > 2)
intel_private.gtt = ioremap_wc(intel_private.gtt_bus_addr,
gtt_map_size);
if (intel_private.gtt == NULL)