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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 A3325C43461 for ; Tue, 1 Sep 2020 15:01:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FBDD207D3 for ; Tue, 1 Sep 2020 15:01:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="afn94a0r" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728299AbgIAPBP (ORCPT ); Tue, 1 Sep 2020 11:01:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725989AbgIAPBK (ORCPT ); Tue, 1 Sep 2020 11:01:10 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B360DC061244; Tue, 1 Sep 2020 08:01:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=c4Ee9icQII2DGAoMrIbwKT8Ude3XzoISGtg+XB13lKQ=; b=afn94a0rd08dIeIK+nPtOLy9ZF 2kHzRnga5rpNnJdpfqAdEkDoDXnbQLFe53sru0CkEghz/uu1jDS/OLaSJ+nTqEjhT34UhvcmEEJIY MqjQVEuWOQeiiEIl9BzC7QTXM3oeEPCjpJZW0uTROZyy/No0zCe/etHYanQR7sMptJckLhBj1ciT8 pB3s3YkIryDdSN+nEtCUxp7av0xGykhSncbcxwlkFtcNGZVMyZ4FT31TI2XkJIpM72reeWASyq8Lo 1Es0Ru63eoYj9KldC//FQZ4EIGB9kRInPDRT/Y1JbvmfYRhsX3+W+/83DND1k4IpIOTaeVkdknDH/ mlMV2o1Q==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kD7mL-0004dC-KN; Tue, 01 Sep 2020 15:00:57 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 770E6300F7A; Tue, 1 Sep 2020 17:00:55 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6633520BEB41B; Tue, 1 Sep 2020 17:00:55 +0200 (CEST) Date: Tue, 1 Sep 2020 17:00:55 +0200 From: peterz@infradead.org To: Ulf Hansson Cc: Naresh Kamboju , paulmck@kernel.org, "Rafael J. Wysocki" , Saravana Kannan , open list , linux-mmc , lkft-triage@lists.linaro.org, rcu@vger.kernel.org, Linux PM , Anders Roxell , Arnd Bergmann , Rajendra Nayak , John Stultz , Stephen Boyd , Lars Povlsen , madhuparnabhowmik10@gmail.com, Viresh Kumar , Vincent Guittot , Lina Iyer , Thomas Gleixner Subject: Re: WARNING: suspicious RCU usage - sdhci-pltfm: SDHCI platform and OF driver helper Message-ID: <20200901150055.GD2674@hirez.programming.kicks-ass.net> References: <20200831194402.GD2855@paulmck-ThinkPad-P72> <20200901104206.GU1362448@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 01, 2020 at 02:35:52PM +0200, Ulf Hansson wrote: > On Tue, 1 Sep 2020 at 12:42, wrote: > > That said; I pushed the rcu_idle_enter() about as deep as it goes into > > generic code in commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle > > deeper into the idle path") > > Aha, that commit should fix this problem, I think. Looks like that > commit was sent as a fix and included in the recent v5.9-rc3. AFAICT psci_enter_domain_idle_state() is still buggered. All that pm_runtime_*() stuff is using locks. Look at this: psci_enter_domain_idle_state() pm_runtime_put_sync_suspend() __pm_runtime_suspend() spin_lock_irqsave(&dev->power.lock, flags); That's a definite fail after we've done rcu_idle_enter(). > > I suppose the next step is pushing it into individual driver when > > needed, something like the below perhaps. I realize the coupled idle > > state stuff is more complicated that most, but it's also not an area > > I've looked at in detail, so perhaps I've just made a bigger mess, but > > it ought to give you enough to get going I think. > > These aren't coupled states. Instead, in cpuidle-psci, we are using PM > domains through genpd and runtime PM to manage "shared idle states" > between CPUs. Similar problem I'm thinking, 'complicated' stuff.