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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47F4EC433FE for ; Mon, 4 Oct 2021 13:21:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F73E613D5 for ; Mon, 4 Oct 2021 13:21:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236505AbhJDNWt (ORCPT ); Mon, 4 Oct 2021 09:22:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:33046 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236580AbhJDNUu (ORCPT ); Mon, 4 Oct 2021 09:20:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9225561994; Mon, 4 Oct 2021 13:08:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633352934; bh=4tqAWzyryKYmgALVAX8+oJ1ZlePLWu4Bus+uT4VdClg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JSZqW1BkGheuUOAClHpq9O2ZWeHX8iIy2cO1DunyEM1I/ximJLopQ9e/bfUZGS+zX QW+Z8zL4isDolC0zSIFg3pxPADYbWof0CvFYpGHjUeg0ZvJLXd67ketLwtYIR4vaZU 3/MCYfSYH8sbT8NheTDrJdiZvZ3U/wqIUoEDW8K8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Fertser , Guenter Roeck Subject: [PATCH 5.10 09/93] hwmon: (tmp421) handle I2C errors Date: Mon, 4 Oct 2021 14:52:07 +0200 Message-Id: <20211004125034.893357112@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211004125034.579439135@linuxfoundation.org> References: <20211004125034.579439135@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul Fertser commit 2938b2978a70d4cc10777ee71c9e512ffe4e0f4b upstream. Function i2c_smbus_read_byte_data() can return a negative error number instead of the data read if I2C transaction failed for whatever reason. Lack of error checking can lead to serious issues on production hardware, e.g. errors treated as temperatures produce spurious critical temperature-crossed-threshold errors in BMC logs for OCP server hardware. The patch was tested with Mellanox OCP Mezzanine card emulating TMP421 protocol for temperature sensing which sometimes leads to I2C protocol error during early boot up stage. Fixes: 9410700b881f ("hwmon: Add driver for Texas Instruments TMP421/422/423 sensor chips") Cc: stable@vger.kernel.org Signed-off-by: Paul Fertser Link: https://lore.kernel.org/r/20210924093011.26083-1-fercerpav@gmail.com [groeck: dropped unnecessary line breaks] Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/hwmon/tmp421.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) --- a/drivers/hwmon/tmp421.c +++ b/drivers/hwmon/tmp421.c @@ -119,38 +119,56 @@ static int temp_from_u16(u16 reg) return (temp * 1000 + 128) / 256; } -static struct tmp421_data *tmp421_update_device(struct device *dev) +static int tmp421_update_device(struct tmp421_data *data) { - struct tmp421_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; + int ret = 0; int i; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + (HZ / 2)) || !data->valid) { - data->config = i2c_smbus_read_byte_data(client, - TMP421_CONFIG_REG_1); + ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1); + if (ret < 0) + goto exit; + data->config = ret; for (i = 0; i < data->channels; i++) { - data->temp[i] = i2c_smbus_read_byte_data(client, - TMP421_TEMP_MSB[i]) << 8; - data->temp[i] |= i2c_smbus_read_byte_data(client, - TMP421_TEMP_LSB[i]); + ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]); + if (ret < 0) + goto exit; + data->temp[i] = ret << 8; + + ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]); + if (ret < 0) + goto exit; + data->temp[i] |= ret; } data->last_updated = jiffies; data->valid = 1; } +exit: mutex_unlock(&data->update_lock); - return data; + if (ret < 0) { + data->valid = 0; + return ret; + } + + return 0; } static int tmp421_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { - struct tmp421_data *tmp421 = tmp421_update_device(dev); + struct tmp421_data *tmp421 = dev_get_drvdata(dev); + int ret = 0; + + ret = tmp421_update_device(tmp421); + if (ret) + return ret; switch (attr) { case hwmon_temp_input: