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From: Heiko Stuebner <heiko@sntech.de>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org, linux-rockchip@lists.infradead.org,
	Klaus Goger <klaus.goger@theobroma-systems.com>
Subject: cpufreq(-dt) with two clocks but one regulator
Date: Fri, 15 Sep 2017 00:53:42 +0200	[thread overview]
Message-ID: <1515316.mHJbnBRRvK@phil> (raw)

Hi Viresh,

if possible I'd like a pointer in the right direction for the following
situation:

The rk3368 has two cpu clusters of 4 Cortex-A53 cores each, with separate
clock supplies but sharing its supplying regulator. It looks like it was
originally meant for some switched big-little system, with the little
cluster maxing out at 1.2GHz while the big cluster can reach 1.5GHz.

This of course fails miserably with current cpufreq, as the two sets
of operating points fight over control of the regulator and after talking
with real-life users of the soc it seems most desireable to have all
8 cores available at 1.2GHz than only 4 at 1.5GHz max.

But as the clock seems to be bound to the opp table itself simply sharing
the table of course also doesn't work, as only the first clock would be set.


I'm currently only seeing somehow hacky options to solve this, so if you
have some direction on how to solve something like this I would be really
grateful :-)


Thanks
Heiko

             reply	other threads:[~2017-09-14 22:53 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-14 22:53 Heiko Stuebner [this message]
2017-09-18  1:24 ` cpufreq(-dt) with two clocks but one regulator Viresh Kumar
2017-09-18 22:40   ` Heiko Stuebner
2017-09-18 23:37     ` Doug Anderson
2017-09-19  9:19       ` Heiko Stübner
2017-09-19 15:25         ` Viresh Kumar

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