treewide: Use IS_ERR_OR_NULL over manual NULL check - refactor

[PATCH 57/61] reset: Prefer IS_ERR_OR_NULL over manual NULL check

Posted by Philipp Hahn 4 weeks, 1 day ago

Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL
check.

Semantich change: Previously the code only printed the warning on error,
but not when the pointer was NULL. Now the warning is printed in both
cases!

Change found with coccinelle.

To: Philipp Zabel <p.zabel@pengutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Philipp Hahn <phahn-oss@avm.de>
---
 drivers/reset/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index fceec45c8afc1e74fe46311bdc023ff257e8d770..649bb4ebabb20a09349ccbfc62f8280621df450e 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -715,7 +715,7 @@ EXPORT_SYMBOL_GPL(reset_control_bulk_acquire);
  */
 void reset_control_release(struct reset_control *rstc)
 {
-	if (!rstc || WARN_ON(IS_ERR(rstc)))
+	if (WARN_ON(IS_ERR_OR_NULL(rstc)))
 		return;
 
 	if (reset_control_is_array(rstc))

-- 
2.43.0

Re: [PATCH 57/61] reset: Prefer IS_ERR_OR_NULL over manual NULL check

Posted by Masami Hiramatsu (Google) 4 weeks, 1 day ago

On Tue, 10 Mar 2026 12:49:23 +0100
Philipp Hahn <phahn-oss@avm.de> wrote:

> Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL
> check.
> 
> Semantich change: Previously the code only printed the warning on error,
> but not when the pointer was NULL. Now the warning is printed in both
> cases!
> 
> Change found with coccinelle.
> 
> To: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Philipp Hahn <phahn-oss@avm.de>
> ---
>  drivers/reset/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/reset/core.c b/drivers/reset/core.c
> index fceec45c8afc1e74fe46311bdc023ff257e8d770..649bb4ebabb20a09349ccbfc62f8280621df450e 100644
> --- a/drivers/reset/core.c
> +++ b/drivers/reset/core.c
> @@ -715,7 +715,7 @@ EXPORT_SYMBOL_GPL(reset_control_bulk_acquire);
>   */
>  void reset_control_release(struct reset_control *rstc)
>  {
> -	if (!rstc || WARN_ON(IS_ERR(rstc)))
> +	if (WARN_ON(IS_ERR_OR_NULL(rstc)))

This changes the behavior when rstc == NULL.
WARN_ON does not hit when rstc == NULL in the original code.

Thanks,

>  		return;
>  
>  	if (reset_control_is_array(rstc))
> 
> -- 
> 2.43.0
> 
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>

Re: [PATCH 57/61] reset: Prefer IS_ERR_OR_NULL over manual NULL check

Posted by Philipp Zabel 4 weeks, 1 day ago

Hi Philipp,

On Di, 2026-03-10 at 12:49 +0100, Philipp Hahn wrote:
> Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL
> check.
>
> Semantich change: Previously the code only printed the warning on error,
> but not when the pointer was NULL. Now the warning is printed in both
> cases!

No, rstc == NULL is valid (for optional reset controls) and must not
throw a warning.


regards
Philipp