linux-kernel - Re: [PATCH RESEND v8 04/10] watchdog: rzg2l_wdt: Check return status of pm_runtime

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Message-ID: <7985bafe-80ff-412c-b6e5-6db6da6b8323@tuxon.dev>
Date: Thu, 11 Apr 2024 17:07:46 +0300
From: claudiu beznea <claudiu.beznea@...on.dev>
To: Guenter Roeck <linux@...ck-us.net>
Cc: wim@...ux-watchdog.org, robh@...nel.org, krzk+dt@...nel.org,
 conor+dt@...nel.org, p.zabel@...gutronix.de, geert+renesas@...der.be,
 magnus.damm@...il.com, biju.das.jz@...renesas.com,
 linux-watchdog@...r.kernel.org, devicetree@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-renesas-soc@...r.kernel.org,
 Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
Subject: Re: [PATCH RESEND v8 04/10] watchdog: rzg2l_wdt: Check return status
 of pm_runtime_put()



On 10.04.2024 19:41, Guenter Roeck wrote:
> On Wed, Apr 10, 2024 at 04:40:38PM +0300, Claudiu wrote:
>> From: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
>>
>> pm_runtime_put() may return an error code. Check its return status.
>>
>> Along with it the rzg2l_wdt_set_timeout() function was updated to
>> propagate the result of rzg2l_wdt_stop() to its caller.
>>
>> Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
>> ---
>>
>> Changes in v8:
>> - none
>>
>> Changes in v7:
>> - none
>>
>> Changes in v6:
>> - none
>>
>> Changes in v5:
>> - none
>>
>> Changes in v4:
>> - none
>>
>> Changes in v3:
>> - none
>>
>> Changes in v2:
>> - propagate the return code of rzg2l_wdt_stop() to it's callers
>>
>>
>>  drivers/watchdog/rzg2l_wdt.c | 11 +++++++++--
>>  1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
>> index d87d4f50180c..7bce093316c4 100644
>> --- a/drivers/watchdog/rzg2l_wdt.c
>> +++ b/drivers/watchdog/rzg2l_wdt.c
>> @@ -144,9 +144,13 @@ static int rzg2l_wdt_start(struct watchdog_device *wdev)
>>  static int rzg2l_wdt_stop(struct watchdog_device *wdev)
>>  {
>>  	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
>> +	int ret;
>>  
>>  	rzg2l_wdt_reset(priv);
>> -	pm_runtime_put(wdev->parent);
>> +
>> +	ret = pm_runtime_put(wdev->parent);
>> +	if (ret < 0)
>> +		return ret;
> 
> Nit:
> 	return pm_runtime_put(wdev->parent);
> 
> would have been sufficient.
> 

pm_runtime_put() may return 1 if the device is already suspended. Further
explained in v1 of this series:

https://lore.kernel.org/all/92db308f-075c-4799-9777-5bc14438ce68@tuxon.dev/

> Nevertheless,
> 
> Reviewed-by: Guenter Roeck <linux@...ck-us.net>
> 
>>  
>>  	return 0;
>>  }
>> @@ -163,7 +167,10 @@ static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int time
>>  	 * to reset the module) so that it is updated with new timeout values.
>>  	 */
>>  	if (watchdog_active(wdev)) {
>> -		rzg2l_wdt_stop(wdev);
>> +		ret = rzg2l_wdt_stop(wdev);
>> +		if (ret)
>> +			return ret;
>> +
>>  		ret = rzg2l_wdt_start(wdev);
>>  	}
>>  
>> -- 
>> 2.39.2
>>