linux-kernel - [PATCH] drm/amdgpu: shut up #warning for compile testing

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Message-Id: <20170201155943.1740947-1-arnd@arndb.de>
Date:   Wed,  1 Feb 2017 16:59:21 +0100
From:   Arnd Bergmann <arnd@...db.de>
To:     Alex Deucher <alexander.deucher@....com>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Christian König <christian.koenig@....com>,
        David Airlie <airlied@...ux.ie>,
        Chunming Zhou <David1.Zhou@....com>,
        Flora Cui <Flora.Cui@....com>,
        Michel Dänzer <michel.daenzer@....com>,
        Nicolai Hähnle <nicolai.haehnle@....com>,
        Junwei Zhang <Jerry.Zhang@....com>,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] drm/amdgpu: shut up #warning for compile testing

My randconfig tests on linux-next showed a newly introduced warning:

drivers/gpu/drm/amd/amdgpu/amdgpu_object.c: In function 'amdgpu_bo_create_restricted':
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c:377:2: error: #warning Please enable CONFIG_MTRR and CONFIG_X86_PAT for better performance thanks to write-combining [-Werror=cpp]

Generally speaking, warnings about bad kernel configuration are not particularly
helpful. We could enforce the selection of X86_PAT through Kconfig, so the driver
cannot even be used unless it is enabled, or we could just rely on the runtime
warning that is also there.

In this version, I'm making the warning conditional on CONFIG_COMPILE_TEST, which
shuts it up for me, but not people that may actually want to run the kernel
as a compromize.

Fixes: a2e2f29970aa ("drm/amdgpu: Bring bo creation in line with radeon driver (v2)")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index d1aa291b2638..da3a53a39d0b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -374,8 +374,10 @@ int amdgpu_bo_create_restricted(struct amdgpu_device *adev,
 	 * 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 & AMDGPU_GEM_CREATE_CPU_GTT_USWC)
 		DRM_INFO_ONCE("Please enable CONFIG_MTRR and CONFIG_X86_PAT for "
-- 
2.9.0