diff mbox series

[AUTOSEL,4.14,13/69] hwmon: (ina2xx) Fix current value calculation

Message ID 20181205094247.6556-13-sashal@kernel.org (mailing list archive)
State Not Applicable
Headers show
Series None | expand

Commit Message

Sasha Levin Dec. 5, 2018, 9:41 a.m. UTC 
From: Nicolin Chen <nicoleotsuka@gmail.com>

[ 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 <nicoleotsuka@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/ina2xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

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: