From martinjonestechnology@googlemail.com Thu Apr 02 09:12:28 2009 Received: from mail-ew0-f163.google.com ([209.85.219.163]) by stoneboat.aleph1.co.uk with esmtp (Exim 4.69) (envelope-from ) id 1LpI2A-0007Jj-JQ for balloon@balloonboard.org; Thu, 02 Apr 2009 09:12:28 +0100 Received: by ewy7 with SMTP id 7so460962ewy.13 for ; Thu, 02 Apr 2009 01:12:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=je0UTqMg0ZFei80AdvMjDe86O3rAnDAs9fTRGOPYY3c=; b=Dh2j3KoNd7qlUW2dgi0BDwr5gGzJotIoVW9D19tTBKcuokRhwBFU2DpB+TqK8lBVp/ zJ8RX3dzWc572FtamDadlFRtm25IzDlVAsUG7lGD77OQWdVCki6ZCfXt0PTElJC6t3UK nlypQHWsAzLu6fhpVeT2P7ZvdXaS7jtBpD6zk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=jiNTbrCs79AX/tPEorbdCq4OKdmbUw2fe+asEiDpPhcn3XeqxHzECMQG1UBEqrZgui BqaLFpTh2aculro3N0mI0E3CvFfd0GhrZj02iWCYKN7jil+qor9TDyUNT2gTCPlA69QE 8h0+2lWJ/sSxOwfv72e7ynnymhiuywfcSEKxg= Received: by 10.216.0.208 with SMTP id 58mr2898381web.216.1238659936994; Thu, 02 Apr 2009 01:12:16 -0700 (PDT) Received: from ?192.168.1.6? (cpc4-cmbg1-0-0-cust759.cmbg.cable.ntl.com [82.21.110.248]) by mx.google.com with ESMTPS id u14sm1693093gvf.19.2009.04.02.01.12.15 (version=TLSv1/SSLv3 cipher=RC4-MD5); Thu, 02 Apr 2009 01:12:16 -0700 (PDT) Sender: Chris Jones Message-ID: <49D47369.2040803@martin-jones.com> Date: Thu, 02 Apr 2009 09:12:25 +0100 From: Chris Jones User-Agent: Thunderbird 2.0.0.21 (Windows/20090302) MIME-Version: 1.0 To: Jonathan McDowell References: <49D3B00A.4030806@martin-jones.com> <20090401220605.GB5306@earth.li> In-Reply-To: <20090401220605.GB5306@earth.li> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 209.85.219.163 X-SA-Exim-Mail-From: martinjonestechnology@googlemail.com X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on stoneboat.aleph1.co.uk X-Spam-Level: X-Spam-Status: No, score=-2.6 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.2.5 X-SA-Exim-Version: 4.2.1 (built Wed, 25 Jun 2008 17:14:11 +0000) X-SA-Exim-Scanned: Yes (on stoneboat.aleph1.co.uk) Cc: balloon@balloonboard.org Subject: Re: [Balloon] 2.6.29-rc7 kernel power management X-BeenThere: balloon@balloonboard.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Balloon List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Apr 2009 08:12:28 -0000 Jonathan McDowell wrote: > On Wed, Apr 01, 2009 at 07:18:50PM +0100, Chris Jones wrote: >> I've been doing some work on L3 standby power this afternoon, the >> primary upshot of which is that there are now hooks in >> /arch/arm/mach-pxa/balloon3.c for doing things on the way into and out >> of standby. I cribbed most of the code straight from palmz72.c which >> seemed to have the right sort of things in it, so if there's a >> better/more legitimate way to do it, I'm open to ideas. > > Is this code in SVN now? I'm currently concentrating on getting the base > balloon3 support into mainline kernels, but I'll have a look if that > ever gets done. Yes - I folded the changes into balloon3.patch. >> The same issue arises with the Samosa bus - did parking the bus lines >> ever get in after the grand TCL kernel hacking session? I can't see it >> in the code. > > No, this didn't get added so you're not missing anything. OK. If I was to put in the relevant code, I assume it would go at the tail end of samosa_suspend_late() and the head end of samosa_resume_early(), bracketing the power management of the devices on the bus. >> Thinking about these things and looking at the code indicates to me >> that making the relevant control registers in Balloon 3's programmable >> logic read/write or at least set/reset rather than write-only would >> make life somewhat easier in the kernel, but could introduce >> incompatibilities. > > If necessary we can keep local copies of the state and provide accessor > functions, but being able to query the hardware or at least only frob > the bits we need to would be much cleaner. I propose making the registers set/reset, since: - it uses less logic resource in the hardware than making them readable - I've already got a VHDL module which does the job - it makes changing individual bits an atomic operation, leaving no gap between a read and a writeback which could get interrupted There are a couple of bits we need to be able to read, as well. Hold tight for a Balloon 3 register remap. Chris -- Chris Jones - chris@martin-jones.com Martin-Jones Technology Ltd, makers of Solidlights 148 Catharine Street, Cambridge, CB1 3AR, UK Phone +44 (0) 1223 655611 Fax +44 (0) 870 112 3908 http://www.solidlights.co.uk/