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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78C3FC54EED for ; Mon, 30 Jan 2023 13:04:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230464AbjA3NEW convert rfc822-to-8bit (ORCPT ); Mon, 30 Jan 2023 08:04:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230374AbjA3NEW (ORCPT ); Mon, 30 Jan 2023 08:04:22 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 646731724 for ; Mon, 30 Jan 2023 05:04:21 -0800 (PST) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4P57b04r1yz6H7MZ; Mon, 30 Jan 2023 21:00:44 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Mon, 30 Jan 2023 13:04:19 +0000 Date: Mon, 30 Jan 2023 13:04:18 +0000 From: Jonathan Cameron To: =?ISO-8859-1?Q?M=E5rten?= Lindahl CC: Jonathan Cameron , Lars-Peter Clausen , Andy Shevchenko , , Subject: Re: [PATCH] iio: light: vcnl4000: Fix WARN_ON on uninitialized lock Message-ID: <20230130130418.000013ce@Huawei.com> In-Reply-To: <20230130093742.838577-1-marten.lindahl@axis.com> References: <20230130093742.838577-1-marten.lindahl@axis.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8BIT X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500003.china.huawei.com (7.191.162.67) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Mon, 30 Jan 2023 10:37:42 +0100 Mårten Lindahl wrote: > There are different init functions for the sensors in this driver in > which only one initialize the generic vcnl4000_lock. With commit > e21b5b1f2 ("iio: light: vcnl4000: Preserve conf bits when toggle power") > the vcnl4040 sensor started to depend on the lock, but it was missed to > initialize it in vcnl4040's init function. This has not been visible > until we run lockdep on it: > > DEBUG_LOCKS_WARN_ON(lock->magic != lock) > WARNING: CPU: 1 PID: 8800 at kernel/locking/mutex.c:575 __mutex_lock+0x4f8/0x890 > ... > Call trace: > __mutex_lock > mutex_lock_nested > vcnl4200_set_power_state > vcnl4200_init > vcnl4000_probe > i2c_device_probe > really_probe > __driver_probe_device > driver_probe_device > __driver_attach > bus_for_each_dev > driver_attach > bus_add_driver > driver_register > i2c_register_driver > vcnl4000_driver_init > do_one_initcall > do_init_module > load_module > __do_sys_finit_module > ... > > Fix this by adding mutex_init on the lock in the init function used for > vcnl4040. > > Fixes: e21b5b1f2 ("iio: light: vcnl4000: Preserve conf bits when toggle power") > Signed-off-by: Mårten Lindahl Perhaps better to pull the lock out of the device specific setup? > --- > drivers/iio/light/vcnl4000.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c > index cc1a2062e76d..a8a9fc3b1a02 100644 > --- a/drivers/iio/light/vcnl4000.c > +++ b/drivers/iio/light/vcnl4000.c > @@ -316,6 +316,7 @@ static int vcnl4200_init(struct vcnl4000_data *data) > } > mutex_init(&data->vcnl4200_al.lock); > mutex_init(&data->vcnl4200_ps.lock); > + mutex_init(&data->vcnl4000_lock); > > ret = data->chip_spec->set_power_state(data, true); > if (ret < 0)