From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3C97C07E85 for ; Mon, 3 Dec 2018 15:39:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6AB32087F for ; Mon, 3 Dec 2018 15:39:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C6AB32087F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=atomide.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726732AbeLCPjW (ORCPT ); Mon, 3 Dec 2018 10:39:22 -0500 Received: from muru.com ([72.249.23.125]:56134 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726560AbeLCPjW (ORCPT ); Mon, 3 Dec 2018 10:39:22 -0500 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id E041880BF; Mon, 3 Dec 2018 15:39:19 +0000 (UTC) Date: Mon, 3 Dec 2018 07:39:10 -0800 From: Tony Lindgren To: Stephen Boyd Cc: Tero Kristo , Andreas Kemnade , bcousson@baylibre.com, letux-kernel@openphoenux.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, mturquette@baylibre.com, paul@pwsan.com Subject: Re: [PATCH v2 2/3] clk: ti: check clock type before doing autoidle ops Message-ID: <20181203153910.GA6707@atomide.com> References: <20181110203115.13335-1-andreas@kemnade.info> <20181110203115.13335-3-andreas@kemnade.info> <154353750560.88331.11814738542436183126@swboyd.mtv.corp.google.com> <20181130071534.0a6cd455@kemnade.info> <154356242517.88331.8496814814468751012@swboyd.mtv.corp.google.com> <9eb7b090-4803-d389-4112-3bf058385b2e@ti.com> <154356463284.88331.13323307899580657085@swboyd.mtv.corp.google.com> <20181130153729.GG53235@atomide.com> <154362191595.88331.15503578806026771935@swboyd.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <154362191595.88331.15503578806026771935@swboyd.mtv.corp.google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Stephen Boyd [181130 23:52]: > Quoting Tony Lindgren (2018-11-30 07:37:29) > > Hi, > > > > * Tero Kristo [181130 09:21]: > > > On 30/11/2018 09:57, Stephen Boyd wrote: > > > > No that is not preferred. Can the omap2_clk_deny_idle() function be > > > > integrated closer into the clk framework in some way that allows it to > > > > be part of the clk_ops structure? And then have that take a clk_hw > > > > structure instead of a struct clk? I haven't looked at this in any > > > > detail whatsoever so I may be way off right now. > > > > > > It could be added under the main clk_ops struct, however this would > > > introduce two new func pointers to it which are not used by anything else > > > but OMAP. Are you aware of any other platforms requiring similar feature? > > > > From consumer usage point of view, I'm still wondering about > > the relationship of clk_deny_idle() and clkdm_deny_idle(). > > > > It seems that we need to allow reset control drivers call > > clk_deny_idle() for the duration of reset. And it seems the > > clk_deny_idle() should propagate to also up to the related > > clock domain driver to do clkdm_deny_idle(). > > > > So maybe clk_deny_idle() is could just be something like: > > > > dev = clk_get_device(clk); > > ... > > error = pm_runtime_get(dev); > > ... > > pm_runtime_put(dev); > > ... > > > > And that way it would just propagate to the parent clock > > domain driver and the clock framework does not need to know > > about clockdomains. A clockdomain could be just a genpd > > domain. > > > > Or do you guys have better ideas? > > > > Wouldn't the device link in clk framework patches do this for you if we > had the RUNTIME_PM flag passed in. If this is about keeping the clock > controller active when a consumer device is using it then I think it may > work. The consumer device stays active just fine with PM runtime calls. So yes, the problem is keeping a clock controller forced active for the period of consumer device reset. Other than that typically autoidle can be just kept enabled. Below is a clarified suggested example usage if we wanted to use PM runtime on a clock controller device from a consumer device reset driver: error = pm_runtime_get_dev() ... cdev = clk_get_device(clk); ... error = pm_runtime_get(cdev); ... /* Do the consumer device reset here */ ... pm_runtime_put(cdev); pm_runtime_put(dev); Regards, Tony