From patchwork Tue Apr 5 07:19:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 557664 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 A6D95C4332F for ; Tue, 5 Apr 2022 09:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245531AbiDEJL6 (ORCPT ); Tue, 5 Apr 2022 05:11:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244744AbiDEIwh (ORCPT ); Tue, 5 Apr 2022 04:52:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B62981CB32; Tue, 5 Apr 2022 01:43:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 51B0E61003; Tue, 5 Apr 2022 08:43:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6708CC385A0; Tue, 5 Apr 2022 08:43:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649148188; bh=GDkhXDUtppKjqDANeL6Q/shPJCjo5cy4GQ0T5NVoiQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WZQbN95K9EBRtdqpSllJR1uP6FKFO8DMUYH+iwIux5Oy/UtcEIOE6eFB6llKYfhDr M3xQGm9nmxMqmW9ft/NE5Lzevvi3+euEIz7d6UboVmOjnn6SXnQxPokPqTsMf8VC2i K55nASfzkVCLfcEywdBNiAmtFZpTCazTWAsvD618= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Patrick Rudolph , Marcello Sylvester Bauer , Alan Tull , Guenter Roeck , Sasha Levin Subject: [PATCH 5.16 0227/1017] hwmon: (pmbus) Add mutex to regulator ops Date: Tue, 5 Apr 2022 09:19:00 +0200 Message-Id: <20220405070400.992560063@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Patrick Rudolph [ Upstream commit 686d303ee6301261b422ea51e64833d7909a2c36 ] On PMBUS devices with multiple pages, the regulator ops need to be protected with the update mutex. This prevents accidentally changing the page in a separate thread while operating on the PMBUS_OPERATION register. Tested on Infineon xdpe11280 while a separate thread polls for sensor data. Signed-off-by: Patrick Rudolph Signed-off-by: Marcello Sylvester Bauer Link: https://lore.kernel.org/r/b991506bcbf665f7af185945f70bf9d5cf04637c.1645804976.git.sylv@sylv.io Fixes: ddbb4db4ced1b ("hwmon: (pmbus) Add regulator support") Cc: Alan Tull Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/pmbus/pmbus_core.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index ac2fbee1ba9c..b1386a4df4cc 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -2391,10 +2391,14 @@ static int pmbus_regulator_is_enabled(struct regulator_dev *rdev) { struct device *dev = rdev_get_dev(rdev); struct i2c_client *client = to_i2c_client(dev->parent); + struct pmbus_data *data = i2c_get_clientdata(client); u8 page = rdev_get_id(rdev); int ret; + mutex_lock(&data->update_lock); ret = pmbus_read_byte_data(client, page, PMBUS_OPERATION); + mutex_unlock(&data->update_lock); + if (ret < 0) return ret; @@ -2405,11 +2409,17 @@ static int _pmbus_regulator_on_off(struct regulator_dev *rdev, bool enable) { struct device *dev = rdev_get_dev(rdev); struct i2c_client *client = to_i2c_client(dev->parent); + struct pmbus_data *data = i2c_get_clientdata(client); u8 page = rdev_get_id(rdev); + int ret; - return pmbus_update_byte_data(client, page, PMBUS_OPERATION, - PB_OPERATION_CONTROL_ON, - enable ? PB_OPERATION_CONTROL_ON : 0); + mutex_lock(&data->update_lock); + ret = pmbus_update_byte_data(client, page, PMBUS_OPERATION, + PB_OPERATION_CONTROL_ON, + enable ? PB_OPERATION_CONTROL_ON : 0); + mutex_unlock(&data->update_lock); + + return ret; } static int pmbus_regulator_enable(struct regulator_dev *rdev)