Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752744AbbHCJQ2 (ORCPT ); Mon, 3 Aug 2015 05:16:28 -0400 Received: from down.free-electrons.com ([37.187.137.238]:57733 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752621AbbHCJQ1 (ORCPT ); Mon, 3 Aug 2015 05:16:27 -0400 Date: Mon, 3 Aug 2015 11:16:24 +0200 From: Maxime Ripard To: Julian Calaby Cc: 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 , Chen-Yu Tsai Subject: Re: [linux-sunxi] [PATCH] ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to a level all boards can supply Message-ID: <20150803091624.GZ2564@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="FgR7z6dKxNwpUCN/" 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: 2372 Lines: 64 --FgR7z6dKxNwpUCN/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Aug 03, 2015 at 09:35:51AM +1000, Julian Calaby wrote: > Hi Timo, >=20 > On Mon, Aug 3, 2015 at 5:23 AM, Timo Sigurdsson > wrote: > > sun7i-a20.dtsi contains an cpufreq operating point at 0.9 volts. Most A= 20 boards > > (or all?), however, do not allow the voltage to go below 1.0V. Thus, ra= ise the > > voltage for the lowest operating point to 1.0V so all boards can actual= ly use > > it. >=20 > Surely it wouldn't be added here if some could supply 0.9v. >=20 > 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? And how would it choose between the two exactly ? Switch to the 144MHz @ 0.9V and see if it works ? If it doesn't you might have screwed your system already, and might not be able to recover from it at all. Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --FgR7z6dKxNwpUCN/ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVvzFoAAoJEBx+YmzsjxAg2+AP/2Cws1bmgg1HkWqHms6mfBNv ZuW69O74momUpEsMq58OeVznkRpX3J5HssGELqyVyqwG8BNAhAOwiTNWi2M+d++w 9uQCcZZKmSc0mP/urhSYbVkLTiJjWUOsKEcnkvAV1NcFqxSC1mjsJTldeokB72Oc wB5QoHzP1p1SJf9zGJLbmhjM9jF/xBiaOUr1/rTICLbMg6s1g0PAp+wnkkSUgDL8 l1DtQ5831QOXNW1cXMMQYNJQZqeko2wTa0MJwVBVEDonBjkmzlDYg/TEmDanDZm5 ZhpFDcufSUsxNHxVHjBEgLe3ag5twz+i/uvCk0JZ1nxGoYAO6mrZqFkjx6vPFOef 2fk2itbzd0zAsPSwZfxmYTP8yGExkLnLC0zEWPW9ei2jVgkJzu4WncnY80uDHSdA mnXC9g+PStX8WxEE8LlglKSDjdtNEv8xYe1aQdhKiwbC0DA4C38tnZ2+6WbZgIZ0 Pi4ZHckvzwpb2WYWTJ2HFCGlO4vCPF4ws/wng780NiBKe2WO6HecEKXo+6R6F6Rj bmNaMs/W8sakgT+yzQgRQi+pJ2V5dPPtzI+1oUAYM5Nd9wXdzIfVp2UX3wmZ4Nfc X2VQ49b+oiM043UwosXYKZ2j82+n4eL7L+yyOKvcqndyXlcnNDxUMNBh66wi8MWN OO/Nyj5M47WUccd3xHk5 =Ro4m -----END PGP SIGNATURE----- --FgR7z6dKxNwpUCN/-- -- 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/