Re: [PATCH 2/5] cpufreq: governor: Create separate sysfs-ops

From: Rafael J. Wysocki
Date: Wed Feb 03 2016 - 08:38:54 EST


On Wed, Feb 3, 2016 at 2:21 PM, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> On 03-02-16, 13:42, Rafael J. Wysocki wrote:
>> > +static ssize_t governor_show(struct kobject *kobj, struct attribute *attr,
>> > + char *buf)
>> > +{
>> > + struct dbs_data *dbs_data = to_dbs_data(kobj);
>> > + struct governor_attr *gattr = to_gov_attr(attr);
>> > + int ret = -EIO;
>> > +
>> > + down_read(&dbs_data->rwsem);
>> > +
>> > + if (gattr->show)
>> > + ret = gattr->show(dbs_data, buf);
>> > +
>> > + up_read(&dbs_data->rwsem);
>>
>> Do we need the lock here too?
>>
>> show() is only going to read the value, isn't it? And everything u32
>> or smaller is read atomically anyway.
>
> Okay, will drop it for now.
>
>> Apart from this it looks good to me.
>>
>> When you're ready, please resend the whole series without patch [5/5]
>> which is premature IMO.
>
> I have changed that patch a bit, and am dropping just the lock now and
> not governor_enable thing. That should be sane enough I believe.

In any case this is not suitable for 4.5 IMO.

> Anyway I will be posting 7 patches now, pick only first 4 if you
> aren't confident about the rest.

OK

Thanks,
Rafael