[3.19.y-ckt stable] Patch "drm/radeon: mask out WC from BO on unsupported arches" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    drm/radeon: mask out WC from BO on unsupported arches

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt16.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

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>From 56957426a39c60a3792c0d58d689b6b6195eb749 Mon Sep 17 00:00:00 2001
From: Oded Gabbay <oded.gabbay at gmail.com>
Date: Sat, 30 Jan 2016 07:59:33 +0200
Subject: drm/radeon: mask out WC from BO on unsupported arches
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Content-Type: text/plain; charset=UTF-8
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commit c5244987394648913ae1a03879c58058a2fc2cee upstream.

Reviewed-by: Christian König <christian.koenig at amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer at amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay at gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/radeon/radeon_object.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index 826564d..586a10d 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -33,6 +33,7 @@
 #include <linux/slab.h>
 #include <drm/drmP.h>
 #include <drm/radeon_drm.h>
+#include <drm/drm_cache.h>
 #include "radeon.h"
 #include "radeon_trace.h"

@@ -244,6 +245,12 @@ int radeon_bo_create(struct radeon_device *rdev,
 	DRM_INFO_ONCE("Please enable CONFIG_MTRR and CONFIG_X86_PAT for "
 		      "better performance thanks to write-combining\n");
 	bo->flags &= ~RADEON_GEM_GTT_WC;
+#else
+	/* For architectures that don't support WC memory,
+	 * mask out the WC flag from the BO
+	 */
+	if (!drm_arch_can_wc_memory())
+		bo->flags &= ~RADEON_GEM_GTT_WC;
 #endif

 	radeon_ttm_placement_from_domain(bo, domain);
--
2.7.0