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,USER_AGENT_MUTT autolearn=ham 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 783FFC169C4 for ; Fri, 8 Feb 2019 11:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52AEE217D8 for ; Fri, 8 Feb 2019 11:51:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727308AbfBHLvc (ORCPT ); Fri, 8 Feb 2019 06:51:32 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:49616 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726522AbfBHLvc (ORCPT ); Fri, 8 Feb 2019 06:51:32 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 958F880D; Fri, 8 Feb 2019 03:51:31 -0800 (PST) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A69823F719; Fri, 8 Feb 2019 03:51:29 -0800 (PST) Date: Fri, 8 Feb 2019 11:51:22 +0000 From: Sudeep Holla To: Marek Szyprowski Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Viresh Kumar , "Rafael J . Wysocki" , Nishanth Menon , Stephen Boyd , Bartlomiej Zolnierkiewicz , Dave Gerlach , Wolfram Sang Subject: Re: [PATCH 0/2] cpufreq/opp: rework regulator initialization Message-ID: <20190208115122.GA13043@e107155-lin> References: <20190207122227.19873-1-m.szyprowski@samsung.com> <20190208110053.GA7913@e107155-lin> <87302853-74cc-8eeb-6bd4-6338746e0738@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87302853-74cc-8eeb-6bd4-6338746e0738@samsung.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 08, 2019 at 12:47:06PM +0100, Marek Szyprowski wrote: > Hi Sudeep, > > On 2019-02-08 12:00, Sudeep Holla wrote: > > On Thu, Feb 07, 2019 at 01:22:25PM +0100, Marek Szyprowski wrote: > >> Dear All, > >> > >> This is a scenario that triggers the above issue: > > [...] > >> 1. system disables non-boot cpu's at the end of system suspend procedure, > >> 2. this in turn deinitializes cpufreq drivers for the disabled cpus, > >> 3. early in the system resume procedure all cpus are got back to online > >> state, > >> 4. this in turn causes cpufreq to be initialized for the newly onlined > >> cpus, > >> 5. cpufreq-dt acquires all its resources (clocks, regulators) during > >> ->init() callback, > > This is strictly not just restricted to cpufreq-dt, but to any driver > > supporting multiple policies. So we need a generic fix not just > > cpufreq-dt specific. > > Could you point which other driver needs similar fix? Here in cpufreq-dt > the problem was caused by using regulator api (indirectly) from > ->init(). All other drivers, which have regulators support, are for old, > obsolete, uni-processor systems, which don't have the problem of > secondary cpu suspend during system suspend/resume cycle. > scmi_cpufreq for instance. We can fix that in driver my moving to polling to get cpufreq_get_rate, but we support both polling and interrupt based. We may wait for remote processor interrupt in get_rate. -- Regards, Sudeep