Re: [PATCH 01/15] counter: rz-mtu3-cnt: put runtime PM on initialization error path

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 14 Sep 2026 23:36:00 +0300
Cosmin Tanislav <cosmin-gabriel.tanislav.xa@renesas.com> wrote:

> If rz_mtu3_initialize_counter() fails, the runtime PM usage count is not
> decremented.
> 
> rz_mtu3_initialize_counter() will fail if the requested channel is busy.
> 
> Call pm_runtime_put() in the error path to decrement the usage count,
> and flip the check to keep the success path straightforward.
> 
> Cc: stable@vger.kernel.org
> Fixes: 0be8907359df ("counter: Add Renesas RZ/G2L MTU3a counter driver")
> Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@renesas.com>
> ---
>  drivers/counter/rz-mtu3-cnt.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/counter/rz-mtu3-cnt.c b/drivers/counter/rz-mtu3-cnt.c
> index 7bfb6979193c..48f183f0b54f 100644
> --- a/drivers/counter/rz-mtu3-cnt.c
> +++ b/drivers/counter/rz-mtu3-cnt.c
> @@ -506,8 +506,12 @@ static int rz_mtu3_count_enable_write(struct counter_device *counter,
>  	if (enable) {
>  		pm_runtime_get_sync(counter->parent);
>  		ret = rz_mtu3_initialize_counter(counter, count->id);
> -		if (ret == 0)
> -			priv->count_is_enabled[count->id] = true;
> +		if (ret) {
> +			pm_runtime_put(counter->parent);
> +			goto exit;

I'd use a guard() for the mutex and return here and one more case
above. Not quite the minimal fix, but will give a more readable result.

> +		}
> +
> +		priv->count_is_enabled[count->id] = true;
>  	} else {
>  		rz_mtu3_terminate_counter(counter, count->id);
>  		priv->count_is_enabled[count->id] = false;