From patchwork Fri Dec 20 09:47:39 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 3387201 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6A0A9C0D4A for ; Fri, 20 Dec 2013 09:50:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B9F3320166 for ; Fri, 20 Dec 2013 09:50:51 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6EDD5206D9 for ; Fri, 20 Dec 2013 09:50:50 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vtwhr-0006dq-Gs; Fri, 20 Dec 2013 09:49:20 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VtwhS-0004v9-Fv; Fri, 20 Dec 2013 09:48:54 +0000 Received: from galois.linutronix.de ([2001:470:1f0b:db:abcd:42:0:1]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vtwgn-0004po-Sn for linux-arm-kernel@lists.infradead.org; Fri, 20 Dec 2013 09:48:16 +0000 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1VtwgR-00024R-KP; Fri, 20 Dec 2013 10:47:51 +0100 From: Sebastian Andrzej Siewior To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/8] ARM: Convert boot_lock to raw_lock [exynos] Date: Fri, 20 Dec 2013 10:47:39 +0100 Message-Id: <1387532866-22601-2-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 1.8.5.1 In-Reply-To: <1387532866-22601-1-git-send-email-bigeasy@linutronix.de> References: <1387532866-22601-1-git-send-email-bigeasy@linutronix.de> X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001, URIBL_BLOCKED=0.001 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131220_044814_283176_159F34CB X-CRM114-Status: GOOD ( 12.48 ) X-Spam-Score: -2.4 (--) Cc: Kukjin Kim , Frank Rowand , Sebastian Andrzej Siewior , linux-samsung-soc@vger.kernel.org, Frank Rowand , Thomas Gleixner X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Frank Rowand The arm boot_lock is used by the secondary processor startup code. The locking task is the idle thread, which has idle->sched_class == &idle_sched_class. idle_sched_class->enqueue_task == NULL, so if the idle task blocks on the lock, the attempt to wake it when the lock becomes available will fail: try_to_wake_up() ... activate_task() enqueue_task() p->sched_class->enqueue_task(rq, p, flags) Fix by converting boot_lock to a raw spin lock. Cc: Kukjin Kim Cc: linux-samsung-soc@vger.kernel.org Cc: Frank Rowand Signed-off-by: Frank Rowand Link: http://lkml.kernel.org/r/4E77B952.3010606@am.sony.com Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior --- arch/arm/mach-exynos/platsmp.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c index 58b43e6..f56f767 100644 --- a/arch/arm/mach-exynos/platsmp.c +++ b/arch/arm/mach-exynos/platsmp.c @@ -73,7 +73,7 @@ static void __iomem *scu_base_addr(void) return (void __iomem *)(S5P_VA_SCU); } -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); static void exynos_secondary_init(unsigned int cpu) { @@ -86,8 +86,8 @@ static void exynos_secondary_init(unsigned int cpu) /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) @@ -99,7 +99,7 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) * Set synchronisation state between this boot processor * and the secondary one */ - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * The secondary processor is waiting to be released from @@ -128,7 +128,7 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) if (timeout == 0) { printk(KERN_ERR "cpu1 power enable failed"); - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return -ETIMEDOUT; } } @@ -167,7 +167,7 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; }