From 822130b5e8834ab30ad410cf19a582e5014b9a85 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 7 Jul 2023 13:11:51 +0200 Subject: [PATCH] drm/amdgpu: avoid integer overflow warning in amdgpu_device_resize_fb_bar() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit On 32-bit architectures comparing a resource against a value larger than U32_MAX can cause a warning: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:1344:18: error: result of comparison of constant 4294967296 with expression of type 'resource_size_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare] res->start > 0x100000000ull) ~~~~~~~~~~ ^ ~~~~~~~~~~~~~~ As gcc does not warn about this in dead code, add an IS_ENABLED() check at the start of the function. This will always return success but not actually resize the BAR on 32-bit architectures without high memory, which is exactly what we want here, as the driver can fall back to bank switching the VRAM access. Fixes: 31b8adab3247 ("drm/amdgpu: require a root bus window above 4GB for BAR resize") Reviewed-by: Christian König Signed-off-by: Arnd Bergmann Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 7f069e1731fe..fcf5f07c4775 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -1325,6 +1325,9 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev) u16 cmd; int r; + if (!IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT)) + return 0; + /* Bypass for VF */ if (amdgpu_sriov_vf(adev)) return 0; -- 2.25.1