drm/nouveau: ltc/gf100-: fix cbc issues on certain boards

commit fe3d9c4b upstream.

A mismatch between FB and LTC's idea of how big a large page is causes
issues such as black "holes" in rendering to occur on some boards
(those where LTC is configured for 64KiB large pages) when compression
is used.

Confirmed to fix at least the GK107 MBP.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
[ kamal: backport to 3.13-stable: subdev/ltc/ not present in 3.13 ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/gpu/drm/nouveau/core/subdev/bar/nvc0.c

@@ -198,7 +198,6 @@ nvc0_bar_init(struct nouveau_object *object)
 
 	nv_mask(priv, 0x000200, 0x00000100, 0x00000000);
 	nv_mask(priv, 0x000200, 0x00000100, 0x00000100);
-	nv_mask(priv, 0x100c80, 0x00000001, 0x00000000);
 
 	nv_wr32(priv, 0x001704, 0x80000000 | priv->bar[1].mem->addr >> 12);
 	nv_wr32(priv, 0x001714, 0xc0000000 | priv->bar[0].mem->addr >> 12);

drivers/gpu/drm/nouveau/core/subdev/fb/nvc0.c

@@ -45,6 +45,7 @@ nvc0_fb_init(struct nouveau_object *object)
 
 	if (priv->r100c10_page)
 		nv_wr32(priv, 0x100c10, priv->r100c10 >> 8);
+	nv_mask(priv, 0x100c80, 0x00000001, 0x00000000); /* 128KiB lpg */
 	return 0;
 }