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From: Paul Walmsley <paul.walmsley@sifive.com>
To: Carlos Eduardo de Paula <me@carlosedp.com>
Cc: linux-riscv@lists.infradead.org
Subject: Re: Changing SiFive Unleashed core clock rate on 5.x kernel
Date: Tue, 13 Aug 2019 19:09:13 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.21.9999.1908131908000.19217@viisi.sifive.com> (raw)
In-Reply-To: <alpine.DEB.2.21.9999.1908131417450.29979@viisi.sifive.com>

On Tue, 13 Aug 2019, Paul Walmsley wrote:

> On Mon, 12 Aug 2019, Carlos Eduardo de Paula wrote:
> 
> > Now with Kernel 5.x and with the board DTB, what's the correct way to
> > set this clock rate?
> 
> There are some experimental patches here:
> 
> https://github.com/sifive/riscv-linux/tree/dev/paulw/cpufreq-dt-aloe-v5.3-rc4
> 
> Only the userspace governor is enabled - for one-off, manual frequency 
> changes, like the one you mentioned above.

By the way, the command lines to change this would be the usual CPUFreq 
sysfs changes.  Something like this:

echo userspace > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
echo 1400000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed


- Paul

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  reply	other threads:[~2019-08-14  2:09 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-12 20:32 Changing SiFive Unleashed core clock rate on 5.x kernel Carlos Eduardo de Paula
2019-08-13 21:22 ` Paul Walmsley
2019-08-14  2:09   ` Paul Walmsley [this message]
2019-08-16 18:59     ` Carlos Eduardo de Paula
2019-08-16 19:50       ` Paul Walmsley
2019-08-16 20:50         ` Carlos Eduardo de Paula
2019-08-16 20:57           ` Paul Walmsley
2019-08-16 21:17             ` Carlos Eduardo de Paula
2019-08-16 21:44               ` Carlos Eduardo de Paula

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