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 at arndb.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