Re: [PATCH 1/5] watchdog: starfive-wdt: Drop runtime PM reference if starting watchdog fails

[Tzung-Bi Shih <tzungbi@kernel.org>]

On Wed, Nov 04, 2026 at 08:44:41AM -0800, Guenter Roeck wrote:
> Commit 8f0ca55016a7 ("watchdog: starfive-wdt: Fix runtime PM leak in
> starfive_wdt_pm_start()") switched starfive_wdt_pm_start() to
> pm_runtime_resume_and_get() so the runtime PM usage counter is not
> leaked when resuming the device fails. However, if starfive_wdt_start()
> subsequently fails (for example, on a timeout in starfive_wdt_int_clr()),
> starfive_wdt_pm_start() returns the error without releasing the runtime
> PM reference acquired by pm_runtime_resume_and_get(). Because the
> watchdog core does not invoke the stop callback when start fails, the
> usage counter remains permanently elevated.
> 
> Drop the runtime PM reference with pm_runtime_put_sync() if
> starfive_wdt_start() fails.
> 
> Fixes: db728ea9c7be ("drivers: watchdog: Add StarFive Watchdog driver")
> Cc: Xingyu Wu <xingyu.wu@starfivetech.com>
> Cc: Ziv Xu <ziv.xu@starfivetech.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

With a nit,

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

> @@ -372,12 +372,17 @@ static void starfive_wdt_stop(struct starfive_wdt *wdt)
>  static int starfive_wdt_pm_start(struct watchdog_device *wdd)
>  {
>  	struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
> -	int ret = pm_runtime_resume_and_get(wdd->parent);
> +	int ret;
>  
> +	ret = pm_runtime_resume_and_get(wdd->parent);
>  	if (ret < 0)
>  		return ret;
>  
> -	return starfive_wdt_start(wdt);
> +	ret = starfive_wdt_start(wdt);
> +	if (ret)
> +		pm_runtime_put_sync(wdd->parent);
> +
> +	return ret;

Or just `return 0;`.