Messages in this thread Patch in this message | | | From | Nicolin Chen <> | Subject | [PATCH] hwmon: (ina2xx) Fix current value calculation | Date | Tue, 13 Nov 2018 19:48:54 -0800 |
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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.
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> --- 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: -- 2.17.1
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