[PATCH] drm/amdgpu: fix clang out-of-range warning

Arnd Bergmann arnd at kernel.org
Mon Sep 27 12:19:45 UTC 2021


From: Arnd Bergmann <arnd at arndb.de>

clang-14 points out that comparing an 'unsigned int' against a large
64-bit constantn is pointless:

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:1206:18: 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)

Rephrase the comparison using the upper_32_bits() macro, which should
keep it legible while avoiding the warning.

Fixes: 31b8adab3247 ("drm/amdgpu: require a root bus window above 4GB for BAR resize")
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index ab3794c42d36..741a55031ca1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -1203,7 +1203,7 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 
 	pci_bus_for_each_resource(root, res, i) {
 		if (res && res->flags & (IORESOURCE_MEM | IORESOURCE_MEM_64) &&
-		    res->start > 0x100000000ull)
+		    upper_32_bits(res->start) != 0)
 			break;
 	}
 
-- 
2.29.2



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