[PATCH] drm/amdgpu: remove the redundant null check

[PATCH] drm/amdgpu: remove the redundant null check

[zhong jiang]

debugfs_remove and kfree has taken the null check in account.
hence it is unnecessary to check it. Just remove the condition.
No functional change.

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: drm/amdgpu: remove the redundant null check

[Markus Elfring]

> debugfs_remove and kfree has taken the null check in account.
> hence it is unnecessary to check it. Just remove the condition.

How do you think about a wording like the following?

  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.


> No functional change.

I find this information questionable while it is partly reasonable
according to the shown software refactoring.

Can a subject like “[PATCH] drm/amdgpu: Remove two redundant
null pointer checks” be nicer here?


Were any source code analysis tools involved for finding
these update candidates?

Regards,
Markus

Re: drm/amdgpu: remove the redundant null check

[zhong jiang]

On 2019/9/5 1:50, Markus Elfring wrote:
>> debugfs_remove and kfree has taken the null check in account.
>> hence it is unnecessary to check it. Just remove the condition.
> How do you think about a wording like the following?
>
>   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.
>
It's better, Thanks
>> No functional change.
> I find this information questionable while it is partly reasonable
> according to the shown software refactoring.
>
> Can a subject like “[PATCH] drm/amdgpu: Remove two redundant
> null pointer checks” be nicer here?
>
It's more clearer, thanks,  Will repost using above description in v2.
> Were any source code analysis tools involved for finding
> these update candidates?
With the help of Coccinelle. You can find out some example in scripts/coccinelle/.

Sincerely,
zhong jiang
> Regards,
> Markus
>
> .
>

Re: drm/amdgpu: remove the redundant null check

[Markus Elfring]

>> Were any source code analysis tools involved for finding
>> these update candidates?
> With the help of Coccinelle. You can find out some example in scripts/coccinelle/.

Thanks for such background information.
Was the script “ifnullfree.cocci” applied here?

Will it be helpful to add attribution for such tools
to any more descriptions in your patches?

Regards,
Markus

Re: drm/amdgpu: remove the redundant null check

[zhong jiang]

On 2019/9/5 16:38, Markus Elfring wrote:
>>> Were any source code analysis tools involved for finding
>>> these update candidates?
>> With the help of Coccinelle. You can find out some example in scripts/coccinelle/.
> Thanks for such background information.
> Was the script “ifnullfree.cocci” applied here?
Yep
> Will it be helpful to add attribution for such tools
> to any more descriptions in your patches?
Sometimes, I will add the description in my patches. Not always.

Thanks,
zhong jiang
> Regards,
> Markus
>
> .
>

Re: drm/amdgpu: remove the redundant null check

[Alex Deucher]

On Fri, Sep 6, 2019 at 3:01 AM zhong jiang <zhongjiang@huawei.com> wrote:
>
> On 2019/9/5 16:38, Markus Elfring wrote:
> >>> Were any source code analysis tools involved for finding
> >>> these update candidates?
> >> With the help of Coccinelle. You can find out some example in scripts/coccinelle/.
> > Thanks for such background information.
> > Was the script “ifnullfree.cocci” applied here?
> Yep
> > Will it be helpful to add attribution for such tools
> > to any more descriptions in your patches?
> Sometimes, I will add the description in my patches. Not always.

Applied with some minor tweaks to the commit message.

Thanks!

Alex

>
> Thanks,
> zhong jiang
> > Regards,
> > Markus
> >
> > .
> >
>
>
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