From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1755536AbcBCNiv (ORCPT <rfc822;w@1wt.eu>);
	Wed, 3 Feb 2016 08:38:51 -0500
Received: from mail-lf0-f65.google.com ([209.85.215.65]:33580 "EHLO
	mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752124AbcBCNit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 3 Feb 2016 08:38:49 -0500
MIME-Version: 1.0
In-Reply-To: <20160203132140.GE3469@vireshk>
References: <cover.1454410226.git.viresh.kumar@linaro.org>
	<5a012e56b8404e2d07e172b6699ce02f5c5b5f26.1454410226.git.viresh.kumar@linaro.org>
	<CAJZ5v0j4sjyQJoPCE0-XHCtZRTjSZU+xpJJHU3UBci0_v1BDvw@mail.gmail.com>
	<20160203065839.GX31828@vireshk>
	<CAJZ5v0g1ebO_S9YJkZjUNZDHqspBATp3jErRP6RqXCy3zh7NDw@mail.gmail.com>
	<20160203132140.GE3469@vireshk>
Date: Wed, 3 Feb 2016 14:38:47 +0100
X-Google-Sender-Auth: bsvf0-Jvgyyoc1lRcvDpojvPvtY
Message-ID: <CAJZ5v0iUWHPZB6MGK9znQTYZsNNkPwnSN2dwjQ6KMXzFZ6=xeg@mail.gmail.com>
Subject: Re: [PATCH 2/5] cpufreq: governor: Create separate sysfs-ops
From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
        Rafael Wysocki <rjw@rjwysocki.net>, Juri Lelli <juri.lelli@arm.com>,
        Lists linaro-kernel <linaro-kernel@lists.linaro.org>,
        "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
        Saravana Kannan <skannan@codeaurora.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Steve Muckle <steve.muckle@linaro.org>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Morten Rasmussen <morten.rasmussen@arm.com>, dietmar.eggemann@arm.com,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Feb 3, 2016 at 2:21 PM, Viresh Kumar <viresh.kumar@linaro.org> 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