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 B573BC4332F for ; Mon, 4 Oct 2021 13:11:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 99FAF61C14 for ; Mon, 4 Oct 2021 13:11:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236032AbhJDNMu (ORCPT ); Mon, 4 Oct 2021 09:12:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:46410 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235057AbhJDNKv (ORCPT ); Mon, 4 Oct 2021 09:10:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C97A861213; Mon, 4 Oct 2021 13:04:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633352652; bh=io2NPCsfUxpEm+HL50U3w8YEhkK/MtrriuOngdv+6tU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e02/EB75olLtCN/sVbMcbP94cUMH7mMvAgygeYNeu4183JIYgwVCB/aqX83T1m1H7 FKMzQJyZ5CyHpw5FotOA1qeCmAMC/rLUxIcPBZVwz5qVQNSC1vPRFIAeXqEuHzaPw3 Tm9FMGWkHXcEam3p0drGoI3d80orWWEA5ltHpYf0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Fertser , Guenter Roeck , Sasha Levin Subject: [PATCH 4.19 69/95] hwmon: (tmp421) fix rounding for negative values Date: Mon, 4 Oct 2021 14:52:39 +0200 Message-Id: <20211004125035.835738754@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211004125033.572932188@linuxfoundation.org> References: <20211004125033.572932188@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: stable@vger.kernel.org From: Paul Fertser [ Upstream commit 724e8af85854c4d3401313b6dd7d79cf792d8990 ] Old code produces -24999 for 0b1110011100000000 input in standard format due to always rounding up rather than "away from zero". Use the common macro for division, unify and simplify the conversion code along the way. Fixes: 9410700b881f ("hwmon: Add driver for Texas Instruments TMP421/422/423 sensor chips") Signed-off-by: Paul Fertser Link: https://lore.kernel.org/r/20210924093011.26083-3-fercerpav@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/tmp421.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c index c2113c00b635..cdd01a848301 100644 --- a/drivers/hwmon/tmp421.c +++ b/drivers/hwmon/tmp421.c @@ -109,23 +109,17 @@ struct tmp421_data { s16 temp[4]; }; -static int temp_from_s16(s16 reg) +static int temp_from_raw(u16 reg, bool extended) { /* Mask out status bits */ int temp = reg & ~0xf; - return (temp * 1000 + 128) / 256; -} - -static int temp_from_u16(u16 reg) -{ - /* Mask out status bits */ - int temp = reg & ~0xf; - - /* Add offset for extended temperature range. */ - temp -= 64 * 256; + if (extended) + temp = temp - 64 * 256; + else + temp = (s16)temp; - return (temp * 1000 + 128) / 256; + return DIV_ROUND_CLOSEST(temp * 1000, 256); } static struct tmp421_data *tmp421_update_device(struct device *dev) @@ -162,10 +156,8 @@ static int tmp421_read(struct device *dev, enum hwmon_sensor_types type, switch (attr) { case hwmon_temp_input: - if (tmp421->config & TMP421_CONFIG_RANGE) - *val = temp_from_u16(tmp421->temp[channel]); - else - *val = temp_from_s16(tmp421->temp[channel]); + *val = temp_from_raw(tmp421->temp[channel], + tmp421->config & TMP421_CONFIG_RANGE); return 0; case hwmon_temp_fault: /* -- 2.33.0