From patchwork Tue Mar 20 23:40:02 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Walmsley X-Patchwork-Id: 7378 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 1A9EA23E13 for ; Tue, 20 Mar 2012 23:40:06 +0000 (UTC) Received: from mail-iy0-f180.google.com (mail-iy0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id B4357A181AE for ; Tue, 20 Mar 2012 23:40:05 +0000 (UTC) Received: by iage36 with SMTP id e36so960573iag.11 for ; Tue, 20 Mar 2012 16:40:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:date:from :to:cc:subject:in-reply-to:message-id:references:user-agent :mime-version:content-type:x-gm-message-state; bh=4wV+YxWLZVue/pPkXg0u3t/oQdQtdcfxej+jMSdRALw=; b=cTldRM4FXg+Pzh/VmyOUtTqxIUPtpIT0MUlEK8+3DxrzvyxniquW5K2wKn6FGq8FPY VNtzw17CIlsSKg+mg2lJJD0CJUFNh07BXdjW3YMQtcrT0swr/FqZvb1y6SYjK0D5iZS8 QRpikTkqHFmw3ymSJMtiYkAKvk7l5XBnKs1z61ntOJuAa4NF34+bey53v38P0FYGqdA/ m/1tY7qYhdiybAG14vNDkfxhEP7P49qD0V9po96dfFdQm6pzANOIFJGIN2UFJikWMogl NwxGPn//616oh9gmek+uujFJxvdQILjk7X49XHuMKV7McKwhe184HMqxxpnEcwxC7fxd v7Kw== Received: by 10.50.183.163 with SMTP id en3mr1366000igc.12.1332286805063; Tue, 20 Mar 2012 16:40:05 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.231.203.79 with SMTP id fh15csp15519ibb; Tue, 20 Mar 2012 16:40:04 -0700 (PDT) Received: by 10.224.173.141 with SMTP id p13mr3301923qaz.82.1332286803894; Tue, 20 Mar 2012 16:40:03 -0700 (PDT) Received: from utopia.booyaka.com (utopia.booyaka.com. [72.9.107.138]) by mx.google.com with ESMTPS id m10si1252409qcw.69.2012.03.20.16.40.03 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 20 Mar 2012 16:40:03 -0700 (PDT) Received-SPF: pass (google.com: domain of pwsan@booyaka.com designates 72.9.107.138 as permitted sender) client-ip=72.9.107.138; Authentication-Results: mx.google.com; spf=pass (google.com: domain of pwsan@booyaka.com designates 72.9.107.138 as permitted sender) smtp.mail=pwsan@booyaka.com Received: (qmail 20798 invoked by uid 1019); 20 Mar 2012 23:40:02 -0000 Date: Tue, 20 Mar 2012 17:40:02 -0600 (MDT) From: Paul Walmsley To: Arnd Bergmann cc: "Turquette, Mike" , linux-arm-kernel@lists.infradead.org, Amit Kucheria , Nicolas Pitre , linaro-dev@lists.linaro.org, Linus Walleij , Grant Likely , Saravana Kannan , Jeremy Kerr , Magnus Damm , Deepak Saxena , patches@linaro.org, Sascha Hauer , Rob Herring , Russell King , Thomas Gleixner , Richard Zhao , Shawn Guo , Linus Walleij , Mark Brown , Stephen Boyd , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 1/3] Documentation: common clk API In-Reply-To: <201203170905.33191.arnd@arndb.de> Message-ID: References: <1331878280-2758-1-git-send-email-mturquette@linaro.org> <201203170905.33191.arnd@arndb.de> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 X-Gm-Message-State: ALoCoQnAyzFO7knyeWOfDrqUoa2ZT4x4SDFbUifxyLn001PSNxfD7CHEvrrWgN9Oo1MuAeugx7qo Hello Arnd, On Sat, 17 Mar 2012, Arnd Bergmann wrote: > I think it's rather pointless, because the option is not going to > be user selectable but will get selected by the platform unless I'm > mistaken. The platform maintainers that care already know the state > of the framework. This is where we have differing views, I think. Clearly, Sascha, Saravana, Rob, and I have at least slightly different opinions on the durability of the existing API and code. So it seems reasonable to assume that others who have not followed the development of the common clock code might mistake the implementation or API as being stable and well-defined. It sounds like the primary objection is to the use of CONFIG_EXPERIMENTAL. So here is a patch to simply note the status of this code in its Kconfig text. - Paul From: Paul Walmsley Date: Tue, 20 Mar 2012 17:19:06 -0600 Subject: [PATCH] clk: note that the common clk code is still subject to significant change Indicate that the common clk code and API is still likely to require significant change. The API is not well-defined and both it and the underlying mechanics are likely to need significant changes to support non-trivial uses of the rate changing code, such as DVFS with external I/O devices. So any platforms that switch their implementation over to this may need to revise much of their driver code and revalidate their implementations until the behavior of the code is better-defined. A good time for removing this help text would be after at least two platforms that do DVFS on groups of external I/O devices have ported their clock implementations over to the common clk code. Signed-off-by: Paul Walmsley Cc: Mike Turquette --- drivers/clk/Kconfig | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 2eaf17e..dd2d528 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -21,6 +21,11 @@ menuconfig COMMON_CLK this option for loadable modules requiring the common clock framework. + The API and implementation enabled by this option is still + incomplete. The API and implementation is expected to be + fluid and subject to change at any time, potentially + breaking existing users. + If in doubt, say "N". if COMMON_CLK