From patchwork Mon Jan 14 14:23:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Guo X-Patchwork-Id: 1972281 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id B0297DF23A for ; Mon, 14 Jan 2013 14:28:19 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Tuky5-0007S0-GG; Mon, 14 Jan 2013 14:24:54 +0000 Received: from am1ehsobe004.messaging.microsoft.com ([213.199.154.207] helo=am1outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Tuky1-0007Q2-AU for linux-arm-kernel@lists.infradead.org; Mon, 14 Jan 2013 14:24:50 +0000 Received: from mail45-am1-R.bigfish.com (10.3.201.229) by AM1EHSOBE022.bigfish.com (10.3.207.144) with Microsoft SMTP Server id 14.1.225.23; Mon, 14 Jan 2013 14:24:46 +0000 Received: from mail45-am1 (localhost [127.0.0.1]) by mail45-am1-R.bigfish.com (Postfix) with ESMTP id 98CCC2A032F; Mon, 14 Jan 2013 14:24:46 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 4 X-BigFish: VS4(z37d4lzzz1ee6h1de0h1202h1e76h1d1ah1d2ahzz8275dhz2dh87h2a8h668h839hd24he5bhf0ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1155h) X-FB-DOMAIN-IP-MATCH: fail Received: from mail45-am1 (localhost.localdomain [127.0.0.1]) by mail45-am1 (MessageSwitch) id 1358173484961943_25885; Mon, 14 Jan 2013 14:24:44 +0000 (UTC) Received: from AM1EHSMHS008.bigfish.com (unknown [10.3.201.241]) by mail45-am1.bigfish.com (Postfix) with ESMTP id E85CCC0085; Mon, 14 Jan 2013 14:24:44 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by AM1EHSMHS008.bigfish.com (10.3.207.108) with Microsoft SMTP Server (TLS) id 14.1.225.23; Mon, 14 Jan 2013 14:24:44 +0000 Received: from tx30smr01.am.freescale.net (10.81.153.31) by 039-SN1MMR1-001.039d.mgd.msft.net (10.84.1.13) with Microsoft SMTP Server (TLS) id 14.2.318.3; Mon, 14 Jan 2013 14:23:01 +0000 Received: from S2101-09.ap.freescale.net ([10.192.185.115]) by tx30smr01.am.freescale.net (8.14.3/8.14.0) with ESMTP id r0EEMxNX020600; Mon, 14 Jan 2013 07:23:00 -0700 From: Shawn Guo To: Subject: [PATCH v2] ARM: imx: disable cpu in .cpu_kill hook Date: Mon, 14 Jan 2013 22:23:21 +0800 Message-ID: <1358173401-13158-1-git-send-email-shawn.guo@linaro.org> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-OriginatorOrg: sigmatel.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130114_092449_721300_65120126 X-CRM114-Status: GOOD ( 12.14 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [213.199.154.207 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Shawn Guo X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org It's buggy to disable the cpu that is being hot-unplugged in .cpu_die hook which runs on the cpu itself. Instead, it should be done in .cpu_kill which runs on the thread (another cpu) that asks for shutting down the cpu. Move imx_enable_cpu(cpu, false) call into .cpu_kill hook, and leave the cpu to be hot-unplugged in WFI within .cpu_die, so that we can get a more stable cpu hot-plug operation. Signed-off-by: Shawn Guo --- arch/arm/mach-imx/common.h | 1 + arch/arm/mach-imx/hotplug.c | 10 ++++++---- arch/arm/mach-imx/platsmp.c | 1 + 3 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h index 7191ab4..fa36fb8 100644 --- a/arch/arm/mach-imx/common.h +++ b/arch/arm/mach-imx/common.h @@ -142,6 +142,7 @@ extern int imx6q_set_lpm(enum mxc_cpu_pwr_mode mode); extern void imx6q_clock_map_io(void); extern void imx_cpu_die(unsigned int cpu); +extern int imx_cpu_kill(unsigned int cpu); #ifdef CONFIG_PM extern void imx6q_pm_init(void); diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c index 3dec962..7bc5fe1 100644 --- a/arch/arm/mach-imx/hotplug.c +++ b/arch/arm/mach-imx/hotplug.c @@ -46,9 +46,11 @@ static inline void cpu_enter_lowpower(void) void imx_cpu_die(unsigned int cpu) { cpu_enter_lowpower(); - imx_enable_cpu(cpu, false); + cpu_do_idle(); +} - /* spin here until hardware takes it down */ - while (1) - ; +int imx_cpu_kill(unsigned int cpu) +{ + imx_enable_cpu(cpu, false); + return 1; } diff --git a/arch/arm/mach-imx/platsmp.c b/arch/arm/mach-imx/platsmp.c index 3777b80..66fae88 100644 --- a/arch/arm/mach-imx/platsmp.c +++ b/arch/arm/mach-imx/platsmp.c @@ -92,5 +92,6 @@ struct smp_operations imx_smp_ops __initdata = { .smp_boot_secondary = imx_boot_secondary, #ifdef CONFIG_HOTPLUG_CPU .cpu_die = imx_cpu_die, + .cpu_kill = imx_cpu_kill, #endif };