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From: Alexander Kochetkov <al.kochet@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	LAK <linux-arm-kernel@lists.infradead.org>,
	kernel@stlinux.com, Daniel Lezcano <daniel.lezcano@linaro.org>,
	Patrice Chotard <patrice.chotard@st.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH] clocksource/arm_global_timer: reconfigure clockevents after cpufreq change
Date: Tue, 29 Nov 2016 17:05:19 +0300	[thread overview]
Message-ID: <2F6A5074-F54E-4B16-AB3D-DE7301E363FC@gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.20.1611291432290.4358@nanos>

Hello Thomas!

> 29 нояб. 2016 г., в 16:42, Thomas Gleixner <tglx@linutronix.de> написал(а):
> 
> 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 нояб. 2016 г., в 16:42, Thomas Gleixner <tglx@linutronix.de> написал(а):
> 
> 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.

Thank you for help.

Alexander.

  reply	other threads:[~2016-11-29 14:05 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-29 12:15 Alexander Kochetkov
2016-11-29 12:15 ` Alexander Kochetkov
2016-11-29 13:42   ` Thomas Gleixner
2016-11-29 14:05     ` Alexander Kochetkov [this message]
2016-11-29 14:09       ` Thomas Gleixner
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

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