From: Maxime Ripard <maxime.ripard@free-electrons.com>
To: Julian Calaby <julian.calaby@gmail.com>
Cc: Chen-Yu Tsai <wens@csie.org>,
public_timo.s@silentcreek.de, Rob Herring <robh+dt@kernel.org>,
Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
Russell King <linux@arm.linux.org.uk>,
devicetree <devicetree@vger.kernel.org>,
"Mailing List, Arm" <linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-sunxi <linux-sunxi@googlegroups.com>
Subject: Re: [linux-sunxi] [PATCH] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to a level all boards can supply
Date: Mon, 3 Aug 2015 11:28:39 +0200 [thread overview]
Message-ID: <20150803092839.GB2564@lukather> (raw)
In-Reply-To: <CAGRGNgXH90m9h0DDejd5MTf8enduGFQ8dPKrRhmc8Z6y_PaC1w@mail.gmail.com>
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On Mon, Aug 03, 2015 at 02:22:13PM +1000, Julian Calaby wrote:
> >> Is the code that uses this smart enough to sensibly switch between two
> >> operating points with the same frequency and different voltages? If
> >> so, maybe just add a 144MHz @ 1.0v operating point?
> >
> > You could try. Though I really don't see much to gain here.
>
> From what I recall, lower frequency = less power usage, though my
> experience is from x86 laptops, not ARM SoCs and I'm sure I'm missing
> a lot of details. This is the sort of thing that requires thorough
> testing on a dev board.
Not on *a* dev board. On virtually all the A20 SoCs ever produced. If
you have a setting that works better for *your* SoC, fine, patch your
DT, but that's not going to be a default if it's outside of the SoC
operating range.
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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next prev parent reply other threads:[~2015-08-03 9:28 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-02 19:23 [PATCH] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to a level all boards can supply Timo Sigurdsson
2015-08-02 23:35 ` [linux-sunxi] " Julian Calaby
2015-08-03 2:37 ` Chen-Yu Tsai
2015-08-03 4:22 ` Julian Calaby
2015-08-03 4:26 ` Chen-Yu Tsai
2015-08-03 9:03 ` Timo Sigurdsson
2015-08-03 9:34 ` Maxime Ripard
2015-08-03 9:36 ` Julian Calaby
2015-08-04 8:51 ` Timo Sigurdsson
2015-08-03 9:28 ` Maxime Ripard [this message]
2015-08-03 8:37 ` Timo Sigurdsson
2015-08-03 9:23 ` Maxime Ripard
2015-08-03 9:16 ` Maxime Ripard
2015-08-03 9:13 ` Maxime Ripard
2015-08-04 8:38 ` Timo Sigurdsson
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