Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753107AbbHCJ2o (ORCPT ); Mon, 3 Aug 2015 05:28:44 -0400 Received: from down.free-electrons.com ([37.187.137.238]:58174 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753079AbbHCJ2l (ORCPT ); Mon, 3 Aug 2015 05:28:41 -0400 Date: Mon, 3 Aug 2015 11:28:39 +0200 From: Maxime Ripard To: Julian Calaby Cc: Chen-Yu Tsai , public_timo.s@silentcreek.de, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Russell King , devicetree , "Mailing List, Arm" , "linux-kernel@vger.kernel.org" , linux-sunxi Subject: Re: [linux-sunxi] [PATCH] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to a level all boards can supply Message-ID: <20150803092839.GB2564@lukather> References: <1438543386-7253-1-git-send-email-public_timo.s@silentcreek.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="RvfD4wEUHtVM+5Ki" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2267 Lines: 58 --RvfD4wEUHtVM+5Ki Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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. >=20 > From what I recall, lower frequency =3D 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 --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --RvfD4wEUHtVM+5Ki Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVvzRHAAoJEBx+YmzsjxAgHIoP/00AofEhCmTt/DWLHsjS+Kh8 q++o4KV+/pXx9TKFUXuFslDbsSTdgNmGd0mKUORUVGQjhEHYg5bGvitrD+PiPbss ju/LMUBVU3Xdfor1wym6mzkBv+hngeLvyRO76IQw2PNnwoNFOGaqe6YmR8YzkoeH e4UFhWUSVzHUootZdSetKkQa0YcaRd2QSLOAES2WWd5uHL7++E0p3RR6ZrSDgkWR YvynrbpSrYZCpvWU8X1cyBxpB5yzwth38V4cycLcLYetyH2zUdpCfvsKVU3mdupq HGO7dEHrTGZndMijurXUOUBLXVSEXzDvYdtfC5VDM28nmA04dkbVBlpH96+dbz8b qYZaqJqplDkUguPg4xjYcVxkeYe6HXaHFVy1jGxUcrXljcNxYaXkzSOhpfGAadFq 37lQEEPUhQDUdEq+jO0Er5uBgldnFMo/6TsFwljPqE4C7ukBDVTOr30Cz3euxE4u fFGyn9WGPv5kEcAVub0OIp5f1ecSkDrSRJQQjA9dZkICzevddUymPEMw9RnD+3Sw mGQ7V9AiwEoxc7jzW3asAGgqrttRVRZhz4BALZA7hLN8DF/NctWeT4BtMRuSkWBv B0LP+p3vOQxAKqNQFXq5KaQUOSqJDNPvEQ3vnDdLuuCtMbKL3qiX4lIhE8ymPFv5 Z93qTLZI5CXKF8hjZiGJ =3tOe -----END PGP SIGNATURE----- --RvfD4wEUHtVM+5Ki-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/