Re: [PATCH] net: fec: turn on device when extracting statistics
From: David Miller
Date: Mon Nov 28 2016 - 09:12:04 EST
From: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>
Date: Mon, 28 Nov 2016 10:06:31 +0300
>
>
> 28.11.2016 04:29, David Miller пишет:
>> From: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>
>> Date: Fri, 25 Nov 2016 13:02:00 +0300
>>
>>> + int i, ret;
>>> +
>>> + ret = pm_runtime_get_sync(&fep->pdev->dev);
>>> + if (IS_ERR_VALUE(ret)) {
>>> + memset(data, 0, sizeof(*data) * ARRAY_SIZE(fec_stats));
>>> + return;
>>> + }
>>
>> This really isn't the way to do this.
>>
>> When the device is suspended and the clocks are going to be stopped,
>> you must fetch the statistic values into a software copy and provide
>> those if the device is suspended when statistics are requested.
>
> Ok, can do that, although can't see what's wrong with waking device
> here. The situation of requesting stats on down device isn't something
> widely used, thus keeping handling of that as local as possible looks
> better for me.
The issue is the fact that you need error handling at all and might
therefore provide a set of zero stats to the user when that entire
possibility could have been avoided in the first place by recording
the stats at suspend time.