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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 602E3C43381 for ; Fri, 22 Mar 2019 12:46:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FE07218E2 for ; Fri, 22 Mar 2019 12:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553258806; bh=eAglDH3zbOiz0VrCJXk3IOo8oPEmogPYhzJ55yuMeOg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EUVfFOzwGmFSKkwkelIKunfBOc03RCCqI9xdrabhmSc01mbY56V+Zl8L23nLqMk6Q YS/0HtHx2xygMD7QDCV0oNU31MMi1Nkx7Qhu+H0R8mxXQYU5H9KToCYvfOXe9QAaoC QlP76/4syIejr2koBy6GLNCEIqLXhfzSENLFAI/c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387917AbfCVL7K (ORCPT ); Fri, 22 Mar 2019 07:59:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:36070 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387910AbfCVL7F (ORCPT ); Fri, 22 Mar 2019 07:59:05 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0D3322192C; Fri, 22 Mar 2019 11:59:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553255944; bh=eAglDH3zbOiz0VrCJXk3IOo8oPEmogPYhzJ55yuMeOg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v2qcGlFn8un6f8E9VA4oHRCFgJ+0NYEiDH4w5By5JFmsNfhD3waEvgFWotBVju9eI +nsLXRDthknF5VZpEehScE6CC50ZbHRQbvE5Z11t81e+DVgSAdLeT8QeRQdR4Rv1S1 pwCKlbzezN7JGZ4H5GkVxqbkiilOV4+EsgjmvRW0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Russell King , Tony Lindgren , Sasha Levin Subject: [PATCH 4.19 044/280] ARM: OMAP2+: fix lack of timer interrupts on CPU1 after hotplug Date: Fri, 22 Mar 2019 12:13:17 +0100 Message-Id: <20190322111308.798456997@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111306.356185024@linuxfoundation.org> References: <20190322111306.356185024@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 50d6b3cf9403879911e06d69c7ef41e43f8f7b4b ] If we have a kernel configured for periodic timer interrupts, and we have cpuidle enabled, then we end up with CPU1 losing timer interupts after a hotplug. This can manifest itself in RCU stall warnings, or userspace becoming unresponsive. The problem is that the kernel initially wants to use the TWD timer for interrupts, but the TWD loses context when we enter the C3 cpuidle state. Nothing reprograms the TWD after idle. We have solved this in the past by switching to broadcast timer ticks, and cpuidle44xx switches to that mode at boot time. However, there is nothing to switch from periodic mode local timers after a hotplug operation. We call tick_broadcast_enter() in omap_enter_idle_coupled(), which one would expect would take care of the issue, but internally this only deals with one-shot local timers - tick_broadcast_enable() on the other hand only deals with periodic local timers. So, we need to call both. Signed-off-by: Russell King [tony@atomide.com: just standardized the subject line] Signed-off-by: Tony Lindgren Signed-off-by: Sasha Levin --- arch/arm/mach-omap2/cpuidle44xx.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c index a8b291f00109..dae514c8276a 100644 --- a/arch/arm/mach-omap2/cpuidle44xx.c +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -152,6 +152,10 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, mpuss_can_lose_context = (cx->mpu_state == PWRDM_POWER_RET) && (cx->mpu_logic_state == PWRDM_POWER_OFF); + /* Enter broadcast mode for periodic timers */ + tick_broadcast_enable(); + + /* Enter broadcast mode for one-shot timers */ tick_broadcast_enter(); /* @@ -218,15 +222,6 @@ fail: return index; } -/* - * For each cpu, setup the broadcast timer because local timers - * stops for the states above C1. - */ -static void omap_setup_broadcast_timer(void *arg) -{ - tick_broadcast_enable(); -} - static struct cpuidle_driver omap4_idle_driver = { .name = "omap4_idle", .owner = THIS_MODULE, @@ -319,8 +314,5 @@ int __init omap4_idle_init(void) if (!cpu_clkdm[0] || !cpu_clkdm[1]) return -ENODEV; - /* Configure the broadcast timer on each cpu */ - on_each_cpu(omap_setup_broadcast_timer, NULL, 1); - return cpuidle_register(idle_driver, cpu_online_mask); } -- 2.19.1