From 38cd989ee38c16388cde89db5b734f9d55b905f9 Mon Sep 17 00:00:00 2001
From: Nicolin Chen <nicoleotsuka@gmail.com>
Date: Tue, 13 Nov 2018 19:48:54 -0800
Subject: [PATCH] hwmon: (ina2xx) Fix current value calculation
Git-commit: 38cd989ee38c16388cde89db5b734f9d55b905f9
Patch-mainline: v4.20-rc5
References: bsc#1051510
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 <nicoleotsuka@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 c2252cf452f5..07ee19573b3f 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -274,7 +274,7 @@ 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:
--
2.19.1