From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756840Ab1JCQbW (ORCPT ); Mon, 3 Oct 2011 12:31:22 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:36366 "EHLO opensource.wolfsonmicro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753351Ab1JCQbO (ORCPT ); Mon, 3 Oct 2011 12:31:14 -0400 Date: Mon, 3 Oct 2011 17:31:08 +0100 From: Mark Brown To: Rob Herring Cc: Mike Turquette , linux-kernel@vger.kernel.org, paul@pwsan.com, linaro-dev@lists.linaro.org, linus.walleij@stericsson.com, patches@linaro.org, eric.miao@linaro.org, magnus.damm@gmail.com, amit.kucheria@linaro.org, richard.zhao@linaro.org, grant.likely@secretlab.ca, dsaxena@linaro.org, arnd.bergmann@linaro.org, shawn.guo@freescale.com, skannan@quicinc.com, linux@arm.linux.org.uk, jeremy.kerr@canonical.com, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, sboyd@quiinc.com Subject: Re: [PATCH v2 1/7] clk: Add a generic clock infrastructure Message-ID: <20111003163107.GQ3731@opensource.wolfsonmicro.com> References: <1316730422-20027-1-git-send-email-mturquette@ti.com> <1316730422-20027-2-git-send-email-mturquette@ti.com> <4E89C3FA.9020206@gmail.com> <20111003142524.GN3731@opensource.wolfsonmicro.com> <4E89D3C4.8090001@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E89D3C4.8090001@gmail.com> X-Cookie: You will contract a rare disease. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 03, 2011 at 10:24:52AM -0500, Rob Herring wrote: > On 10/03/2011 09:25 AM, Mark Brown wrote: > > This isn't in any way specific to clocks, right now the likely solution > > looks to be Grant's changes for retrying probe() as new devices come on > > line. With that devices can return a code from their probe() which > > tells the driver core that they couldn't get all the resources they need > > and that it should retry the probe() if more devices come on-line. > Except SOC clocks are initialized very early before timers are up and > there can be a very high number of dependencies (every clock except > fixed clocks). With the driver probe retry, retrying is the exception, > not the rule. > Retrying would require every caller to maintain a list of clks to > retry. With 2 stages, you can move that into the core clock code. They don't need to maintain a list of clocks to retry, they need to unwind when probe() fails. But yes. > There are not typically a large number of board-level/driver created > clocks, so ensuring correct register order is not really a problem. In > cases where there is a cross-driver dependency, the probe retry is a > good solution. I dunno, I get the impression that some of this is due to the current limitations of the clock API rather than due to a lack of clocks - perhaps that's specific to the applications I look at, though. applications