From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:55382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729406AbeLEJtS (ORCPT ); Wed, 5 Dec 2018 04:49:18 -0500 From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Nicolin Chen , Guenter Roeck , Sasha Levin , linux-hwmon@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 08/45] hwmon: (ina2xx) Fix current value calculation Date: Wed, 5 Dec 2018 04:46:29 -0500 Message-Id: <20181205094706.7225-8-sashal@kernel.org> In-Reply-To: <20181205094706.7225-1-sashal@kernel.org> References: <20181205094706.7225-1-sashal@kernel.org> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org From: Nicolin Chen [ Upstream commit 38cd989ee38c16388cde89db5b734f9d55b905f9 ] The current register (04h) has a sign bit at MSB. The comments for this calculation also mention that it's a signed register. However, the regval is unsigned type so result of calculation turns out to be an incorrect value when current is negative. This patch simply fixes this by adding a casting to s16. Fixes: 5d389b125186c ("hwmon: (ina2xx) Make calibration register value fixed") Signed-off-by: Nicolin Chen Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/ina2xx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c index 9ac6e1673375..1f291b344178 100644 --- a/drivers/hwmon/ina2xx.c +++ b/drivers/hwmon/ina2xx.c @@ -273,7 +273,7 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg, break; case INA2XX_CURRENT: /* signed register, result in mA */ - val = regval * data->current_lsb_uA; + val = (s16)regval * data->current_lsb_uA; val = DIV_ROUND_CLOSEST(val, 1000); break; case INA2XX_CALIBRATION: -- 2.17.1