[PATCH v2] drm/amdgpu: Remove two redundant null pointer checks

[PATCH v2] drm/amdgpu: Remove two redundant null pointer checks

[zhong jiang]

The functions "debugfs_remove" and "kfree" tolerate the passing
of null pointers. Hence it is unnecessary to check such arguments
around the calls. Thus remove the extra condition check at two places.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 5652cc7..cb94627 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1077,8 +1077,7 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)
 
 	ttm_bo_unlock_delayed_workqueue(&adev->mman.bdev, resched);
 
-	if (fences)
-		kfree(fences);
+	kfree(fences);
 
 	return 0;
 }
@@ -1103,8 +1102,7 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)
 
 void amdgpu_debugfs_preempt_cleanup(struct amdgpu_device *adev)
 {
-	if (adev->debugfs_preempt)
-		debugfs_remove(adev->debugfs_preempt);
+	debugfs_remove(adev->debugfs_preempt);
 }
 
 #else
-- 
1.7.12.4

Re: [PATCH v2] drm/amdgpu: Remove two redundant null pointer checks

[Zhou, David(ChunMing)]

On 2019/9/5 下午1:49, zhong jiang wrote:
> The functions "debugfs_remove" and "kfree" tolerate the passing
> of null pointers. Hence it is unnecessary to check such arguments
> around the calls. Thus remove the extra condition check at two places.
>
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>

Reviewed-by: Chunming Zhou <david1.zhou@amd.com>


> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index 5652cc7..cb94627 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -1077,8 +1077,7 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val)
>   
>   	ttm_bo_unlock_delayed_workqueue(&adev->mman.bdev, resched);
>   
> -	if (fences)
> -		kfree(fences);
> +	kfree(fences);
>   
>   	return 0;
>   }
> @@ -1103,8 +1102,7 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)
>   
>   void amdgpu_debugfs_preempt_cleanup(struct amdgpu_device *adev)
>   {
> -	if (adev->debugfs_preempt)
> -		debugfs_remove(adev->debugfs_preempt);
> +	debugfs_remove(adev->debugfs_preempt);
>   }
>   
>   #else

Re: [v2] drm/amdgpu: Remove two redundant null pointer checks

[Markus Elfring]

> The functions "debugfs_remove" and "kfree" tolerate the passing
> of null pointers. Hence it is unnecessary to check such arguments
> around the calls. Thus remove the extra condition check at two places.

Will a tag like “Generated-by: scripts/coccinelle/free/ifnullfree.cocci” be relevant here?

How do you think about to compare this change approach with another patch variant?

drm/amdgpu: Delete an unnecessary check before two function calls
https://lkml.org/lkml/2019/9/4/401
https://lore.kernel.org/patchwork/patch/1123689/
https://lore.kernel.org/r/a3739125-5fa8-cadb-d2b8-8a9f12e9bacd@web.de/

Regards,
Markus