From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Dirk Brandewie <dirk.brandewie@gmail.com>,
Lists linaro-kernel <linaro-kernel@lists.linaro.org>,
Patch Tracking <patches@linaro.org>,
"cpufreq@vger.kernel.org" <cpufreq@vger.kernel.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Nishanth Menon <nm@ti.com>, Carlos Hernandez <ceh@ti.com>
Subject: Re: [PATCH V2] cpufreq: Make sure CPU is running on a freq from freq-table
Date: Thu, 28 Nov 2013 15:12:57 +0100 [thread overview]
Message-ID: <2065797.S0ijuuXCoe@vostro.rjw.lan> (raw)
In-Reply-To: <CAKohpokyY0ueNXBQn+Vt5A9V65_ko7D5R=iruUzi6cD9YuXOig@mail.gmail.com>
On Thursday, November 28, 2013 07:11:17 PM Viresh Kumar wrote:
> On 28 November 2013 18:39, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> > acpi-cpufreq is one at least.
> >
> > Anyway, this isn't about ACPI or anything like that, but hardware. Generally
> > speaking, on modern Intel hardware the processor itself chooses the frequency
> > to run at and it may do that behind your back. Moreover, it can choose a
> > frequency different from the one you asked for. And it won't choose one that
> > it can't run at for that matter. :-)
> >
> > Overall, I don't believe that the problem you're trying to address is relevant
> > for any non-exotic x86 hardware.
>
> Okay.. So wouldn't it be better that we add this special flag only when we
> face a real problem? Otherwise this flag might stay unused for long time
> and then we might end up removing it..
>
> >> > So there should be a flag for
> >> > drivers indicating whether or not frequencies (or operation points in
> >> > general) are directly testable and the check should only be done for
> >> > the drivers with the flag set.
> >>
> >> Probably a flag with properties exactly opposite to what you mentioned,
> >> so that we don't need to modify most of the drivers..
> >
> > That would work too if you prefer it.
>
> In case we need this flag, what should we name it?
> ALLOW_UNKNOWN_FREQ ??
SKIP_INITIAL_FREQUENCY_CHECK ?
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
next prev parent reply other threads:[~2013-11-28 14:00 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-25 4:23 [PATCH V2] cpufreq: Make sure CPU is running on a freq from freq-table Viresh Kumar
2013-11-25 16:38 ` Dirk Brandewie
2013-11-25 17:01 ` Viresh Kumar
2013-11-25 17:43 ` Dirk Brandewie
2013-11-25 21:13 ` Rafael J. Wysocki
2013-11-26 2:01 ` Viresh Kumar
2013-11-26 6:14 ` viresh kumar
2013-11-26 20:21 ` Rafael J. Wysocki
2013-11-27 3:01 ` Viresh Kumar
2013-11-27 14:22 ` Rafael J. Wysocki
2013-11-27 15:52 ` Viresh Kumar
2013-11-27 20:21 ` Rafael J. Wysocki
2013-11-28 3:20 ` Viresh Kumar
2013-11-28 13:09 ` Rafael J. Wysocki
2013-11-28 13:41 ` Viresh Kumar
2013-11-28 14:12 ` Rafael J. Wysocki [this message]
2013-11-28 14:14 ` Viresh Kumar
2013-11-28 20:31 ` Rafael J. Wysocki
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