[PATCH] Don't test for NULL firmware before releasing

[PATCH] Don't test for NULL firmware before releasing

[Jesper Juhl]

From 4fe34831e2e7677b1c9616356f0a2e0a36ec092f Mon Sep 17 00:00:00 2001
From: Jesper Juhl <jesperjuhl76@gmail.com>
Date: Thu, 16 Feb 2023 02:33:05 +0100
Subject: [PATCH] Don't test for NULL firmware before releasing

release_firmware() tests for a NULL pointer itself, no need to do it up-front.

Signed-off-by: Jesper Juhl <jesperjuhl76@gmail.com>

---
  drivers/gpu/drm/tegra/falcon.c | 3 +--
  1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tegra/falcon.c b/drivers/gpu/drm/tegra/falcon.c
index c0d85463eb1a..ae599441f031 100644
--- a/drivers/gpu/drm/tegra/falcon.c
+++ b/drivers/gpu/drm/tegra/falcon.c
@@ -153,8 +153,7 @@ int falcon_init(struct falcon *falcon)

  void falcon_exit(struct falcon *falcon)
  {
-	if (falcon->firmware.firmware)
-		release_firmware(falcon->firmware.firmware);
+       	release_firmware(falcon->firmware.firmware);
  }

  int falcon_boot(struct falcon *falcon)
-- 
2.39.2

Re: [PATCH] Don't test for NULL firmware before releasing

[Stanislaw Gruszka]

Hi

On Thu, Feb 16, 2023 at 02:37:15AM +0100, Jesper Juhl wrote:
> From 4fe34831e2e7677b1c9616356f0a2e0a36ec092f Mon Sep 17 00:00:00 2001
> From: Jesper Juhl <jesperjuhl76@gmail.com>
> Date: Thu, 16 Feb 2023 02:33:05 +0100
> Subject: [PATCH] Don't test for NULL firmware before releasing
> 
> release_firmware() tests for a NULL pointer itself, no need to do it up-front.
> 
> Signed-off-by: Jesper Juhl <jesperjuhl76@gmail.com>
> 
> ---
>  drivers/gpu/drm/tegra/falcon.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tegra/falcon.c b/drivers/gpu/drm/tegra/falcon.c
> index c0d85463eb1a..ae599441f031 100644
> --- a/drivers/gpu/drm/tegra/falcon.c
> +++ b/drivers/gpu/drm/tegra/falcon.c
> @@ -153,8 +153,7 @@ int falcon_init(struct falcon *falcon)
> 
>  void falcon_exit(struct falcon *falcon)
>  {
> -	if (falcon->firmware.firmware)
> -		release_firmware(falcon->firmware.firmware);
> +       	release_firmware(falcon->firmware.firmware);

Please check patches with checkpatch.pl before posting.

Regards
Stanislaw

Re: [PATCH] Don't test for NULL firmware before releasing

[Mikko Perttunen]

On 2/16/23 15:19, Stanislaw Gruszka wrote:
> Hi
> 
> On Thu, Feb 16, 2023 at 02:37:15AM +0100, Jesper Juhl wrote:
>>  From 4fe34831e2e7677b1c9616356f0a2e0a36ec092f Mon Sep 17 00:00:00 2001
>> From: Jesper Juhl <jesperjuhl76@gmail.com>
>> Date: Thu, 16 Feb 2023 02:33:05 +0100
>> Subject: [PATCH] Don't test for NULL firmware before releasing
>>
>> release_firmware() tests for a NULL pointer itself, no need to do it up-front.
>>
>> Signed-off-by: Jesper Juhl <jesperjuhl76@gmail.com>
>>
>> ---
>>   drivers/gpu/drm/tegra/falcon.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/tegra/falcon.c b/drivers/gpu/drm/tegra/falcon.c
>> index c0d85463eb1a..ae599441f031 100644
>> --- a/drivers/gpu/drm/tegra/falcon.c
>> +++ b/drivers/gpu/drm/tegra/falcon.c
>> @@ -153,8 +153,7 @@ int falcon_init(struct falcon *falcon)
>>
>>   void falcon_exit(struct falcon *falcon)
>>   {
>> -	if (falcon->firmware.firmware)
>> -		release_firmware(falcon->firmware.firmware);
>> +       	release_firmware(falcon->firmware.firmware);
> 
> Please check patches with checkpatch.pl before posting.
> 
> Regards
> Stanislaw
> 

Aside the formatting deficiencies, I'm also not in favor of relying on 
NULL checks inside callees since doing so removes contextual information 
from the programmer; just looking at the code, it is easy to assume the 
pointer cannot be NULL if there is no NULL check. Recently had a longer 
thread about this in the context of kfree in TegraDRM.

Thanks
Mikko