Re: [PATCH v2 04/11] watchdog: rzg2l_wdt: Check return status of pm_runtime_put()

From: claudiu beznea
Date: Wed Jan 31 2024 - 05:36:05 EST


Hi, Biju,

On 31.01.2024 12:32, Biju Das wrote:
> Hi Claudiu,
>
> Thanks for the feedback.
>
>> -----Original Message-----
>> From: Claudiu <claudiu.beznea@xxxxxxxxx>
>> Sent: Wednesday, January 31, 2024 10:20 AM
>> Subject: [PATCH v2 04/11] watchdog: rzg2l_wdt: Check return status of
>> pm_runtime_put()
>>
>> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>>
>> 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@xxxxxxxxxxxxxx>
>> ---
>>
>> 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;
>
> Do we need to check the return code? So far we didn't hit this condition.
> If you are planning to do it, then just
>
> return pm_runtime_put(wdev->parent);

pm_runtime_put() may return 1 if the device is suspended (which is not
considered error) as explained here:

https://patchwork.kernel.org/project/linux-renesas-soc/patch/20240122111115.2861835-4-claudiu.beznea.uj@xxxxxxxxxxxxxx/

Thank you,
Claudiu Beznea

>
> Cheers,
> Biju
>
>>
>> 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
>