From patchwork Fri Mar 7 06:44:40 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 3788101 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 3C060BF540 for ; Fri, 7 Mar 2014 06:48:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 66BB4201F0 for ; Fri, 7 Mar 2014 06:48:07 +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 79C91201B6 for ; Fri, 7 Mar 2014 06:48:06 +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 1WLoY0-0002qb-3A; Fri, 07 Mar 2014 06:46:21 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WLoXb-0000XG-U0; Fri, 07 Mar 2014 06:45:55 +0000 Received: from smtp.codeaurora.org ([198.145.11.231]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WLoWu-0000Qt-2s for linux-arm-kernel@lists.infradead.org; Fri, 07 Mar 2014 06:45:15 +0000 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 9B8B613ECC0; Fri, 7 Mar 2014 06:44:50 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 899E913F128; Fri, 7 Mar 2014 06:44:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, SUSPICIOUS_RECIPS,T_RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=no version=3.3.1 Received: from sboyd-linux.qualcomm.com (i-global252.qualcomm.com [199.106.103.252]) (using TLSv1.1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: sboyd@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id EFC9713EFDC; Fri, 7 Mar 2014 06:44:49 +0000 (UTC) From: Stephen Boyd To: Linus Walleij Subject: [PATCH 1/7] pinctrl: msm: Silence recursive lockdep warning Date: Thu, 6 Mar 2014 22:44:40 -0800 Message-Id: <1394174686-8358-2-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.9.0.1.gd5ccf8c In-Reply-To: <1394174686-8358-1-git-send-email-sboyd@codeaurora.org> References: <1394174686-8358-1-git-send-email-sboyd@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140307_014512_326068_B248129A X-CRM114-Status: GOOD ( 12.90 ) X-Spam-Score: 0.6 (/) Cc: linux-arm-msm@vger.kernel.org, Bjorn Andersson , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org 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-Virus-Scanned: ClamAV using ClamSMTP If a driver calls enable_irq_wake() on a gpio turned interrupt from the msm pinctrl driver we'll get a lockdep warning like so: ============================================= [ INFO: possible recursive locking detected ] 3.14.0-rc3 #2 Not tainted --------------------------------------------- modprobe/52 is trying to acquire lock: (&irq_desc_lock_class){-.....}, at: [] __irq_get_desc_lock+0x48/0x88 but task is already holding lock: (&irq_desc_lock_class){-.....}, at: [] __irq_get_desc_lock+0x48/0x88 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&irq_desc_lock_class); lock(&irq_desc_lock_class); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by modprobe/52: #0: (&__lockdep_no_validate__){......}, at: [] __driver_attach+0x48/0x98 #1: (&__lockdep_no_validate__){......}, at: [] __driver_attach+0x58/0x98 #2: (&irq_desc_lock_class){-.....}, at: [] __irq_get_desc_lock+0x48/0x88 #3: (&(&pctrl->lock)->rlock){......}, at: [] msm_gpio_irq_set_wake+0x20/0xa8 Silence it by putting the gpios into their own lock class. Cc: Bjorn Andersson Signed-off-by: Stephen Boyd --- drivers/pinctrl/pinctrl-msm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/pinctrl/pinctrl-msm.c b/drivers/pinctrl/pinctrl-msm.c index ef2bf3126da6..ac7223dab4a3 100644 --- a/drivers/pinctrl/pinctrl-msm.c +++ b/drivers/pinctrl/pinctrl-msm.c @@ -869,6 +869,12 @@ static void msm_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) chained_irq_exit(chip, desc); } +/* + * This lock class tells lockdep that GPIO irqs are in a different + * category than their parents, so it won't report false recursion. + */ +static struct lock_class_key gpio_lock_class; + static int msm_gpio_init(struct msm_pinctrl *pctrl) { struct gpio_chip *chip; @@ -907,6 +913,7 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl) for (i = 0; i < chip->ngpio; i++) { irq = irq_create_mapping(pctrl->domain, i); + irq_set_lockdep_class(irq, &gpio_lock_class); irq_set_chip_and_handler(irq, &msm_gpio_irq_chip, handle_edge_irq); irq_set_chip_data(irq, pctrl); }