From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Nikula Subject: Re: VDD2 OPP and DSS Date: Wed, 2 Mar 2011 09:18:20 +0200 Message-ID: <20110302091820.0ffd5c5e.jhnikula@gmail.com> References: <1299048012.2226.10.camel@deskari> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ey0-f174.google.com ([209.85.215.174]:59653 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750918Ab1CBHRB (ORCPT ); Wed, 2 Mar 2011 02:17:01 -0500 Received: by eyx24 with SMTP id 24so1954444eyx.19 for ; Tue, 01 Mar 2011 23:17:00 -0800 (PST) In-Reply-To: <1299048012.2226.10.camel@deskari> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tomi Valkeinen Cc: Paul Walmsley , Tero Kristo , "linux-omap@vger.kernel.org" , Vishwanath BS On Wed, 2 Mar 2011 08:40:12 +0200 Tomi Valkeinen wrote: > Hi Paul and Tero, > > Some months ago there were discussions in Nokia about the problem with > VDD2 OPP and DSS fck. The problem was (if I recall right) that the > lowest VDD2 OPP cannot be used if DSS fck is over some certain limit (it > was around 100MHz). If I understood correctly, this was also discussed > with Paul. > > Do you remember this (and did I remember it right =)? What is the status > of this? > At least lower OPP breaks DSS on N900 and Beagle if display is on while entering into lower OPP. This made me thinking that should initial round of "[PATCH 10/13] OMAP3: Add voltage dependency table for VDD1." use only OMAP3430_VDD_CORE_OPP3_UV for core voltage until there's some dynamic/DSS voltage domain support in DSS? http://marc.info/?l=linux-omap&m=129889365901937&w=2 That way, I believe, the DVFS has shorter path to mainline and makes easier to add driver specific support & hooks. DVFS is not only power savings but users are interesting about additional performance too. https://bugs.meego.com/show_bug.cgi?id=13833 -- Jarkko