[PATCH 5.4 093/367] drm/amdgpu: avoid integer overflow warning in amdgpu_device_resize_fb_bar()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


5.4-stable review patch.  If anyone has any objections, please let me know.


From: Arnd Bergmann <arnd@xxxxxxxx>

[ Upstream commit 822130b5e8834ab30ad410cf19a582e5014b9a85 ]

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

Fixes: 31b8adab3247 ("drm/amdgpu: require a root bus window above 4GB for BAR resize")
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
 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 d0e1fd011de54..e5032eb9ae291 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -759,6 +759,9 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 	u16 cmd;
 	int r;
+		return 0;
 	/* Bypass for VF */
 	if (amdgpu_sriov_vf(adev))
 		return 0;

[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux