From: tglx@linutronix.de (Thomas Gleixner)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] clocksource/arm_global_timer: reconfigure clockevents after cpufreq change
Date: Tue, 29 Nov 2016 15:09:46 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1611291508460.4358@nanos> (raw)
In-Reply-To: <2F6A5074-F54E-4B16-AB3D-DE7301E363FC@gmail.com>
On Tue, 29 Nov 2016, Alexander Kochetkov wrote:
> > 29 ????. 2016 ?., ? 16:42, Thomas Gleixner <tglx@linutronix.de> ???????(?):
> >
> > The frequency change would not only affect the clockevent device, it also
> > would affect the clocksource. So the patch is incomplete, but see below.
> Looks like kernel disallow change clocksource and shed_clock rate at
> runtime. I haven?t found any function for that.
>
> > 29 ????. 2016 ?., ? 16:42, Thomas Gleixner <tglx@linutronix.de> ???????(?):
> >
> > That's broken and the clk framework should keep the CORE_PERI clock at a
> > constant rate by reprogramming the divider of the CPU clock.
>
> Thank you for the hint.
>
> > Assumptions w/o real impact are a perfect reason not to apply that
> > patch. This want's a proper proof that the global timer really changes and
> > this hackery is required, which I seriously doubt.
>
> It really changes. It changes like it changes for smp-twd. I guess they are
> driven by same clock CORE_PERI.
If that happens then the whole thing wants to be disabled on those
misconfigured systems and not just hacked for nothing.
Thanks,
tglx
next prev parent reply other threads:[~2016-11-29 14:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-29 12:15 [PATCH] clocksource/arm_global_timer: reconfigure clockevents after cpufreq change Alexander Kochetkov
2016-11-29 12:15 ` Alexander Kochetkov
2016-11-29 13:42 ` Thomas Gleixner
2016-11-29 14:05 ` Alexander Kochetkov
2016-11-29 14:09 ` Thomas Gleixner [this message]
2016-11-29 14:14 ` Marc Zyngier
2016-11-29 14:32 ` Thomas Gleixner
2016-11-29 14:51 ` Marc Zyngier
2016-11-29 15:04 ` Alexander Kochetkov
2016-11-29 14:51 ` Alexander Kochetkov
2016-11-29 15:07 ` Robin Murphy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.20.1611291508460.4358@nanos \
--to=tglx@linutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox