[Intel-gfx] [PATCH] drm/i915: Initialise GTT MTRR to -1

[Chris Wilson]

Fixes a regression from 9e984bc1 (drm/i915: Don't do MTRR setup if PAT
is enabled) where we left the MTRR as 0 and so tried to free a MTRR we
did not own during unload.

Reported-by: Ben Widawsky <ben at bwidawsk.net>
Cc: Ben Widawsky <ben at bwidawsk.net>
Cc: Adam Jackson <ajax at redhat.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_dma.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 67946fa..32d5793 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1928,6 +1928,8 @@ static void
 i915_mtrr_setup(struct drm_i915_private *dev_priv, unsigned long base,
 		unsigned long size)
 {
+	dev_priv->mm.gtt_mtrr = -1;
+
 #if defined(CONFIG_X86_PAT)
 	if (cpu_has_pat)
 		return;
-- 
1.7.9.1