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From:   Arnd Bergmann <arnd@arndb.de>
To:     Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Cc:     Arnd Bergmann <arnd@arndb.de>, stable@vger.kernel.org,
        David Airlie <airlied@linux.ie>,
        Julien Isorce <julien.isorce@gmail.com>,
        Kent Russell <kent.russell@amd.com>,
        Christopher James Halse Rogers 
        <christopher.halse.rogers@canonical.com>,
        Cihangir Akturk <cakturk@gmail.com>,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] radeon: hide pointless #warning when compile testing
Date:   Fri, 16 Feb 2018 16:26:57 +0100
Message-Id: <20180216152713.1628013-1-arnd@arndb.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In randconfig testing, we sometimes get this warning:

drivers/gpu/drm/radeon/radeon_object.c: In function 'radeon_bo_create':
drivers/gpu/drm/radeon/radeon_object.c:242:2: error: #warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance thanks to write-combining [-Werror=cpp]
 #warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance \

This is rather annoying since almost all other code produces no build-time
output unless we have found a real bug. We already fixed this in the
amdgpu driver in commit 31bb90f1cd08 ("drm/amdgpu: shut up #warning for
compile testing") by adding a CONFIG_COMPILE_TEST check last year and
agreed to do the same here, but both Michel and I then forgot about it
until I came across the issue again now.

For stable kernels, as this is one of very few remaining randconfig
warnings in 4.14.

Cc: stable@vger.kernel.org
Link: https://patchwork.kernel.org/patch/9550009/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/radeon/radeon_object.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index 093594976126..54c2b4fc5ead 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -238,9 +238,10 @@ int radeon_bo_create(struct radeon_device *rdev,
 	 * may be slow
 	 * See https://bugs.freedesktop.org/show_bug.cgi?id=88758
 	 */
-
+#ifndef CONFIG_COMPILE_TEST
 #warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance \
 	 thanks to write-combining
+#endif
 
 	if (bo->flags & RADEON_GEM_GTT_WC)
 		DRM_INFO_ONCE("Please enable CONFIG_MTRR and CONFIG_X86_PAT for "
-- 
2.9.0