From patchwork Fri May 25 15:54:41 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 10427865 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 153D3601D5 for ; Fri, 25 May 2018 15:55:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 022F728749 for ; Fri, 25 May 2018 15:55:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EAD8228889; Fri, 25 May 2018 15:54:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5146C28749 for ; Fri, 25 May 2018 15:54:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966912AbeEYPy5 convert rfc822-to-8bit (ORCPT ); Fri, 25 May 2018 11:54:57 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:56755 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966293AbeEYPy4 (ORCPT ); Fri, 25 May 2018 11:54:56 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1fMF3B-0004jv-82; Fri, 25 May 2018 17:54:41 +0200 Date: Fri, 25 May 2018 17:54:41 +0200 From: Sebastian Andrzej Siewior To: "Rafael J. Wysocki" Cc: Linux PM , "Rafael J. Wysocki" , Len Brown , Pavel Machek , Thomas Gleixner , Linux Kernel Mailing List Subject: [PATCH 1/4 v2] PM / suspend: Prevent might sleep splats Message-ID: <20180525155440.jwqrpu3shocwcwjy@linutronix.de> References: <20180525094648.15464-1-bigeasy@linutronix.de> <20180525094648.15464-2-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180323 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Thomas Gleixner timekeeping suspend/resume calls read_persistent_clock() which takes rtc_lock. That results in might sleep warnings because at that point we run with interrupts disabled. We cannot convert rtc_lock to a raw spinlock as that would trigger other might sleep warnings. As a workaround we disable the might sleep warnings by setting system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and restoring it to SYSTEM_RUNNING afer sysdev_resume(). There is no lock contention because hibernate / suspend to RAM is single-CPU at this point. In s2idle's case the system_state is set to SYSTEM_SUSPEND before timekeeping_suspend() which is invoked by the last CPU. In the resume case it set back to SYSTEM_RUNNING after timekeeping_resume() which is invoked by the first CPU in the resume case. The other CPUs will block on tick_freeze_lock. Signed-off-by: Thomas Gleixner [bigeasy: cover s2idle in tick_freeze() / tick_unfreeze()] Signed-off-by: Sebastian Andrzej Siewior --- v1…v2: Moved the s2idle case into tick_freeze()/unfreeze() as suggested by Rafael (tglx was okay with this). include/linux/kernel.h | 1 + kernel/power/hibernate.c | 7 +++++++ kernel/power/suspend.c | 4 ++++ kernel/time/tick-common.c | 2 ++ 4 files changed, 14 insertions(+) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 6a1eb0b0aad9..7aed92624531 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -542,6 +542,7 @@ extern enum system_states { SYSTEM_HALT, SYSTEM_POWER_OFF, SYSTEM_RESTART, + SYSTEM_SUSPEND, } system_state; /* This cannot be an enum because some may be used in assembly source. */ diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 5454cc639a8d..9c85c7822383 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -287,6 +287,8 @@ static int create_image(int platform_mode) local_irq_disable(); + system_state = SYSTEM_SUSPEND; + error = syscore_suspend(); if (error) { pr_err("Some system devices failed to power down, aborting hibernation\n"); @@ -317,6 +319,7 @@ static int create_image(int platform_mode) syscore_resume(); Enable_irqs: + system_state = SYSTEM_RUNNING; local_irq_enable(); Enable_cpus: @@ -445,6 +448,7 @@ static int resume_target_kernel(bool platform_mode) goto Enable_cpus; local_irq_disable(); + system_state = SYSTEM_SUSPEND; error = syscore_suspend(); if (error) @@ -478,6 +482,7 @@ static int resume_target_kernel(bool platform_mode) syscore_resume(); Enable_irqs: + system_state = SYSTEM_RUNNING; local_irq_enable(); Enable_cpus: @@ -563,6 +568,7 @@ int hibernation_platform_enter(void) goto Enable_cpus; local_irq_disable(); + system_state = SYSTEM_SUSPEND; syscore_suspend(); if (pm_wakeup_pending()) { error = -EAGAIN; @@ -575,6 +581,7 @@ int hibernation_platform_enter(void) Power_up: syscore_resume(); + system_state = SYSTEM_RUNNING; local_irq_enable(); Enable_cpus: diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 4c10be0f4843..5149c77506b3 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -428,6 +428,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) arch_suspend_disable_irqs(); BUG_ON(!irqs_disabled()); + system_state = SYSTEM_SUSPEND; + error = syscore_suspend(); if (!error) { *wakeup = pm_wakeup_pending(); @@ -443,6 +445,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) syscore_resume(); } + system_state = SYSTEM_RUNNING; + arch_suspend_enable_irqs(); BUG_ON(irqs_disabled()); diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 49edc1c4f3e6..14de3727b18e 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -490,6 +490,7 @@ void tick_freeze(void) if (tick_freeze_depth == num_online_cpus()) { trace_suspend_resume(TPS("timekeeping_freeze"), smp_processor_id(), true); + system_state = SYSTEM_SUSPEND; timekeeping_suspend(); } else { tick_suspend_local(); @@ -513,6 +514,7 @@ void tick_unfreeze(void) if (tick_freeze_depth == num_online_cpus()) { timekeeping_resume(); + system_state = SYSTEM_RUNNING; trace_suspend_resume(TPS("timekeeping_freeze"), smp_processor_id(), false); } else {