Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753183Ab1EIQBk (ORCPT ); Mon, 9 May 2011 12:01:40 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:44312 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752361Ab1EIQBj (ORCPT ); Mon, 9 May 2011 12:01:39 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=gCORg82RmDNI935sRcQMk8gk+g3kZ653IcixpamwGvjxwEPfOnahXQ3i29xZJLHgtH PbbAez6XFQ7Uwd40Zn8WL2Mzx3aJO1Lf0tz+E1TnvPSj/C1UNZ6mrEjXsc4TqRJpqmS8 QQvvsXM8yCk1udzihYOjQNcQQW5Izb+sC1Ga8= Subject: Re: [PATCH] regulator: Support voltage offsets to compensate for drops in system From: Liam Girdwood To: Mark Brown Cc: linux-kernel@vger.kernel.org, patches@opensource.wolfsonmicro.com In-Reply-To: <1304889217-12319-1-git-send-email-broonie@opensource.wolfsonmicro.com> References: <1304889217-12319-1-git-send-email-broonie@opensource.wolfsonmicro.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 09 May 2011 17:01:35 +0100 Message-ID: <1304956895.3192.16.camel@odin> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1217 Lines: 29 On Sun, 2011-05-08 at 22:13 +0100, Mark Brown wrote: > Some systems, particularly physically large systems used for early > prototyping, may experience substantial voltage drops between the regulator > and the consumers as a result of long traces in the system. With these > systems voltages may need to be set higher than requested in order to > ensure reliable system operation. > > Allow systems to work around such hardware issues by allowing constraints > to supply an offset to be applied to any requested and reported voltages. > This is not ideal, especially since the voltage drop may be load dependant, > but is sufficient for most affected systems, it is not expected to be used > in production hardware. The offset is applied after all constraint > processing so constraints should be specified in terms of consumer values > not physically configured values. > > Signed-off-by: Mark Brown > --- Applied. Thanks Liam -- 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/