[Intel-gfx] [PATCH] drm/i915: Initialize obj->pages before use by i915_gem_object_do_bit17_swizzle()

[Chris Wilson]

If we leave obj->pages set to NULL before attempting to deswizzle them,
then an OOPS is well deserved.

Fixes regression introduced in commit 9da3da660d8c19a54f6e93361d147509be3fff84
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Fri Jun 1 15:20:22 2012 +0100

    drm/i915: Replace the array of pages with a scatterlist

Reported-by: Krzysztof Kolasa
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: stable at vger.kernel.org
---
 drivers/gpu/drm/i915/i915_gem.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ad2ed75..6ab7c68 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1953,10 +1953,11 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 		sg_set_page(sg, page, PAGE_SIZE, 0);
 	}
 
+	obj->pages = st;
+
 	if (i915_gem_object_needs_bit17_swizzle(obj))
 		i915_gem_object_do_bit_17_swizzle(obj);
 
-	obj->pages = st;
 	return 0;
 
 err_pages:
-- 
1.7.10.4