From: Viresh Kumar <viresh.kumar@linaro.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rafael Wysocki <rjw@rjwysocki.net>,
Lists linaro-kernel <linaro-kernel@lists.linaro.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] cpufreq: acpi: policy->driver_data can't be NULL in ->exit()
Date: Wed, 30 Mar 2016 16:51:04 +0530 [thread overview]
Message-ID: <20160330112104.GF24343@vireshk-i7> (raw)
In-Reply-To: <CAJZ5v0hqrUyi2ggsDyOq9y0Q9BzktYdSG6DZQMfMF9HsqRLf0g@mail.gmail.com>
On 30-03-16, 13:15, Rafael J. Wysocki wrote:
> On Wed, Mar 30, 2016 at 6:24 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > Its always set by ->init() and so it will always be there in ->exit().
> > There is no need to have a special check for just that.
>
> I'm not sure what happens if there are two (or more) CPUs in the policy, though.
>
> That case is almost certainly handled incorrectly here (or rather not
> handled at all), but it may just happen to sort of work, because the
> first exiting CPU will clear driver_data and the second one will
> notice that it is NULL now. Of course, that still is racy with
> respect to governors etc, but I'd rather fix the driver properly.
Sorry, I probably didn't understood your comments properly.
But, the core will call ->exit() only for the last exiting CPU. So,
driver_data will never be NULL.
--
viresh
prev parent reply other threads:[~2016-03-30 11:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-30 4:24 [PATCH] cpufreq: acpi: policy->driver_data can't be NULL in ->exit() Viresh Kumar
2016-03-30 11:15 ` Rafael J. Wysocki
2016-03-30 11:18 ` Rafael J. Wysocki
2016-03-30 11:23 ` Viresh Kumar
2016-04-01 8:22 ` Viresh Kumar
2016-04-01 21:00 ` Rafael J. Wysocki
2016-03-30 11:21 ` Viresh Kumar [this message]
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