[RESEND PATCH] PM / devfreq: Fix static checker warning in try_then_request_governor

[RESEND PATCH] PM / devfreq: Fix static checker warning in try_then_request_governor

[Enric Balletbo i Serra]

The patch 23c7b54ca1cd: "PM / devfreq: Fix devfreq_add_device() when
drivers are built as modules." leads to the following static checker
warning:

    drivers/devfreq/devfreq.c:1043 governor_store()
    warn: 'governor' can also be NULL

The reason is that the try_then_request_governor() function returns both
error pointers and NULL. It should just return error pointers, so fix
this by returning a ERR_PTR to the error intead of returning NULL.

Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
---
Hi,

This is a resend of [1] as seems that got lost at some point and I just
noticed that was never merged.

Thanks,
 Enric

[1] https://lkml.org/lkml/2018/10/16/744


 drivers/devfreq/devfreq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 0ae3de76833b..839621b044f4 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -228,7 +228,7 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
  * if is not found. This can happen when both drivers (the governor driver
  * and the driver that call devfreq_add_device) are built as modules.
  * devfreq_list_lock should be held by the caller. Returns the matched
- * governor's pointer.
+ * governor's pointer or an error pointer.
  */
 static struct devfreq_governor *try_then_request_governor(const char *name)
 {
@@ -254,7 +254,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name)
 		/* Restore previous state before return */
 		mutex_lock(&devfreq_list_lock);
 		if (err)
-			return NULL;
+			return ERR_PTR(err);
 
 		governor = find_devfreq_governor(name);
 	}
-- 
2.20.1

RE: [RESEND PATCH] PM / devfreq: Fix static checker warning in try_then_request_governor

[MyungJoo Ham]

>The patch 23c7b54ca1cd: "PM / devfreq: Fix devfreq_add_device() when
>drivers are built as modules." leads to the following static checker
>warning:
>
>    drivers/devfreq/devfreq.c:1043 governor_store()
>    warn: 'governor' can also be NULL
>
>The reason is that the try_then_request_governor() function returns both
>error pointers and NULL. It should just return error pointers, so fix
>this by returning a ERR_PTR to the error intead of returning NULL.
>
>Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.")
>Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
>---
>Hi,
>
>This is a resend of [1] as seems that got lost at some point and I just
>noticed that was never merged.
>
>Thanks,
> Enric

Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>

Thanks!


CHeers,
MyungJoo

Re: [RESEND PATCH] PM / devfreq: Fix static checker warning in try_then_request_governor

[Chanwoo Choi]

Cc: stable@vger.kernel.org

Dear all,

It missed to send this patch to 'stable@vger.kernel.org'.
So, I add it to mailing list.

Regards,
Chanwoo Choi


On 19. 3. 13. 오후 9:22, Enric Balletbo i Serra wrote:
> The patch 23c7b54ca1cd: "PM / devfreq: Fix devfreq_add_device() when
> drivers are built as modules." leads to the following static checker
> warning:
> 
>     drivers/devfreq/devfreq.c:1043 governor_store()
>     warn: 'governor' can also be NULL
> 
> The reason is that the try_then_request_governor() function returns both
> error pointers and NULL. It should just return error pointers, so fix
> this by returning a ERR_PTR to the error intead of returning NULL.
> 
> Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
> ---
> Hi,
> 
> This is a resend of [1] as seems that got lost at some point and I just
> noticed that was never merged.
> 
> Thanks,
>  Enric
> 
> [1] https://lkml.org/lkml/2018/10/16/744
> 
> 
>  drivers/devfreq/devfreq.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 0ae3de76833b..839621b044f4 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -228,7 +228,7 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
>   * if is not found. This can happen when both drivers (the governor driver
>   * and the driver that call devfreq_add_device) are built as modules.
>   * devfreq_list_lock should be held by the caller. Returns the matched
> - * governor's pointer.
> + * governor's pointer or an error pointer.
>   */
>  static struct devfreq_governor *try_then_request_governor(const char *name)
>  {
> @@ -254,7 +254,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name)
>  		/* Restore previous state before return */
>  		mutex_lock(&devfreq_list_lock);
>  		if (err)
> -			return NULL;
> +			return ERR_PTR(err);
>  
>  		governor = find_devfreq_governor(name);
>  	}
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [RESEND PATCH] PM / devfreq: Fix static checker warning in try_then_request_governor

[Greg KH]

On Tue, May 28, 2019 at 10:15:59AM +0900, Chanwoo Choi wrote:
> Cc: stable@vger.kernel.org
> 
> Dear all,
> 
> It missed to send this patch to 'stable@vger.kernel.org'.
> So, I add it to mailing list.

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>