From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755449AbbB0VhV (ORCPT ); Fri, 27 Feb 2015 16:37:21 -0500 Received: from smtp07.smtpout.orange.fr ([80.12.242.129]:52475 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754997AbbB0VhT (ORCPT ); Fri, 27 Feb 2015 16:37:19 -0500 X-ME-Helo: beldin X-ME-Date: Fri, 27 Feb 2015 22:37:15 +0100 X-ME-IP: 109.222.213.148 From: Robert Jarzmik To: Lee Jones Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mturquette@linaro.org, sboyd@codeaurora.org, kernel@stlinux.com, devicetree@vger.kernel.org Subject: Re: [PATCH v3 0/4] clk: st: New always-on clock domain References: <1424799222-9301-1-git-send-email-lee.jones@linaro.org> X-URL: http://belgarath.falguerolles.org/ Date: Fri, 27 Feb 2015 22:37:10 +0100 In-Reply-To: <1424799222-9301-1-git-send-email-lee.jones@linaro.org> (Lee Jones's message of "Tue, 24 Feb 2015 17:33:38 +0000") Message-ID: <87385r3uk9.fsf@free.fr> User-Agent: Gnus/5.130008 (Ma Gnus v0.8) Emacs/24.3.92 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Lee Jones writes: > v2 => v3: > - Ensure DT actually reflects h/w > - i.e. Nodes should not contain a mishmash of different IP > blocks, but should identify related h/w. In the current > example we use interconnects > - Change naming from clkdomain to clk-always-on > - Place "do not abuse" warning in documentation > > v1 => v2: > - Turned the ST specific driver into a generic one > > Hardware can have a bunch of clocks which must not be turned off. > If drivers a) fail to obtain a reference to any of these or b) give > up a previously obtained reference during suspend, the common clk > framework will attempt to turn them off and the hardware will > subsequently die. The only way to recover from this failure is to > restart. > > To avoid either of these two scenarios from catastrophically > disabling the running system we have implemented a clock domain > where clocks are consumed and references are taken, thus preventing > them from being shut down by the framework. Hi Lee, I wonder why there is a need for a new clock when CLK_IGNORE_UNUSED does exist. What is the usecase that is covered by this patchset which is not used by CLK_IGNORE_UNUSED clock flag ? And if that reason exists, I'd like to find it in the commit message. Cheers. -- Robert