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=-4.9 required=3.0 tests=DATE_IN_PAST_96_XX, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS autolearn=ham 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 0BCC4C43381 for ; Tue, 5 Mar 2019 18:09:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD0F220645 for ; Tue, 5 Mar 2019 18:09:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730977AbfCESJK (ORCPT ); Tue, 5 Mar 2019 13:09:10 -0500 Received: from mail1.bemta25.messagelabs.com ([195.245.230.2]:19702 "EHLO mail1.bemta25.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726699AbfCESIc (ORCPT ); Tue, 5 Mar 2019 13:08:32 -0500 Received: from [46.226.52.98] (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits)) by server-2.bemta.az-a.eu-west-1.aws.symcld.net id 80/2D-18573-B1BBE7C5; Tue, 05 Mar 2019 18:08:27 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrEIsWRWlGSWpSXmKPExsVy8IPnUV3p3XU xBlt2qVlMffiEzeLblQ4mi8u75rA5MHvsnHWX3WPTqk42j8+b5AKYo1gz85LyKxJYM1Yf+Mlc cEOo4s/lRywNjLP4uxi5OIQE1jFKLGuYwd7FyAnkVEh8n/WSEcTmFUiWWD2lgwXE5hRwlDjYu 44VosZBovH2XzYQm03AUGLem/dg9SwCqhIbF34HiwsLeEosvj4VrF5EwEOidfsGZhCbWSBW4v y8pSwQ8wUlTs58wgIRl5A4+OIFUA0H0HwtieXHIkHCEgL2EtPfXwULSwjoSzQei4UIGwJd+Y0 FwjaXuL36AesERsFZSIbOQjJ0ASPTKkbzpKLM9IyS3MTMHF1DAwNdQ0MjXUNLY11Tc73EKt1E vdRS3fLU4hJdQ73E8mK94src5JwUvbzUkk2MwPBOKThouYPx1PL0Q4ySHExKorx9XXUxQnxJ+ SmVGYnFGfFFpTmpxYcYZTg4lCR4HXYB5QSLUtNTK9Iyc4CRBpOW4OBREuEV3wmU5i0uSMwtzk yHSJ1i1OU4vfDhXGYhlrz8vFQpcd5TIEUCIEUZpXlwI2BRf4lRVkqYl5GBgUGIpyC1KDezBFX +FaM4B6OSMC8LyBSezLwSuE2vgI5gAjri8+VqkCNKEhFSUg2MvY8+NqkI7n74OWjlLb7g8hUu RQ+OqH2ZqMSgPuWO+rOPCypfXv/ys+XQ+t0hji+KfAxftnE+mHSPzUMxb80Dn88vuET3Mrypf Xl51r6agj2sYc5lL24uW6V2wqpQ5qDwzZI7aQXGX4yKHq1+3GVlJMqamnvJjcFfn9/OXfzNZH 4z9UVFl7VPKLEUZyQaajEXFScCACM38sT1AgAA X-Env-Sender: stwiss.opensource@diasemi.com X-Msg-Ref: server-20.tower-262.messagelabs.com!1551809306!2441267!6 X-Originating-IP: [193.240.73.197] X-SYMC-ESS-Client-Auth: outbound-route-from=pass X-StarScan-Received: X-StarScan-Version: 9.31.5; banners=-,-,- X-VirusChecked: Checked Received: (qmail 30187 invoked from network); 5 Mar 2019 18:08:27 -0000 Received: from unknown (HELO sw-ex-cashub01.diasemi.com) (193.240.73.197) by server-20.tower-262.messagelabs.com with AES128-SHA256 encrypted SMTP; 5 Mar 2019 18:08:27 -0000 Received: from swsrvapps-01.diasemi.com (10.20.28.141) by SW-EX-CASHUB01.diasemi.com (10.20.16.140) with Microsoft SMTP Server id 14.3.408.0; Tue, 5 Mar 2019 18:08:26 +0000 Received: by swsrvapps-01.diasemi.com (Postfix, from userid 22547) id 3322A3FC0F; Tue, 5 Mar 2019 18:08:25 +0000 (GMT) Message-ID: In-Reply-To: References: From: Steve Twiss Date: Tue, 26 Feb 2019 15:32:18 +0000 Subject: [PATCH 05/13] regulator: lp8755: Fix notifier mutex lock warning To: Liam Girdwood , Mark Brown CC: Support Opensource , LKML MIME-Version: 1.0 Content-Type: text/plain X-KSE-AttachmentFiltering-Interceptor-Info: protection disabled X-KSE-ServerInfo: sw-ex-cashub01.diasemi.com, 9 X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 05/03/2019 17:23:00 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The mutex for the regulator_dev must be controlled by the caller of the regulator_notifier_call_chain(), as described in the comment for that function. Failure to mutex lock and unlock surrounding the notifier call results in a kernel WARN_ON_ONCE() which will dump a backtrace for the regulator_notifier_call_chain() when that function call is first made. The mutex can be controlled using the regulator_lock/unlock() API. Fixes: b59320cc5a5e ("regulator: lp8755: new driver for LP8755") Suggested-by: Adam Thomson Signed-off-by: Steve Twiss --- drivers/regulator/lp8755.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/regulator/lp8755.c b/drivers/regulator/lp8755.c index 244822b..d82d307 100644 --- a/drivers/regulator/lp8755.c +++ b/drivers/regulator/lp8755.c @@ -372,10 +372,13 @@ static irqreturn_t lp8755_irq_handler(int irq, void *data) for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++) if ((flag0 & (0x4 << icnt)) && (pchip->irqmask & (0x04 << icnt)) - && (pchip->rdev[icnt] != NULL)) + && (pchip->rdev[icnt] != NULL)) { + regulator_lock(pchip->rdev[icnt]); regulator_notifier_call_chain(pchip->rdev[icnt], LP8755_EVENT_PWR_FAULT, NULL); + regulator_unlock(pchip->rdev[icnt]); + } /* read flag1 register */ ret = lp8755_read(pchip, 0x0E, &flag1); @@ -389,18 +392,24 @@ static irqreturn_t lp8755_irq_handler(int irq, void *data) /* send OCP event to all regualtor devices */ if ((flag1 & 0x01) && (pchip->irqmask & 0x01)) for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++) - if (pchip->rdev[icnt] != NULL) + if (pchip->rdev[icnt] != NULL) { + regulator_lock(pchip->rdev[icnt]); regulator_notifier_call_chain(pchip->rdev[icnt], LP8755_EVENT_OCP, NULL); + regulator_unlock(pchip->rdev[icnt]); + } /* send OVP event to all regualtor devices */ if ((flag1 & 0x02) && (pchip->irqmask & 0x02)) for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++) - if (pchip->rdev[icnt] != NULL) + if (pchip->rdev[icnt] != NULL) { + regulator_lock(pchip->rdev[icnt]); regulator_notifier_call_chain(pchip->rdev[icnt], LP8755_EVENT_OVP, NULL); + regulator_unlock(pchip->rdev[icnt]); + } return IRQ_HANDLED; err_i2c: -- 1.9.3