[PATCH 1/2] power: supply: lego_ev3_battery: Don't ignore iio_read_channel_processed() return value

From: David Lechner
Date: Fri Jul 20 2018 - 16:20:15 EST


This changes the LEGO MINDSTORMS EV3 power supply driver to return an
error if iio_read_channel_processed() fails.

Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---
drivers/power/supply/lego_ev3_battery.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/lego_ev3_battery.c b/drivers/power/supply/lego_ev3_battery.c
index 7b993d669f7f..6e3b3e384172 100644
--- a/drivers/power/supply/lego_ev3_battery.c
+++ b/drivers/power/supply/lego_ev3_battery.c
@@ -39,7 +39,7 @@ static int lego_ev3_battery_get_property(struct power_supply *psy,
union power_supply_propval *val)
{
struct lego_ev3_battery *batt = power_supply_get_drvdata(psy);
- int val2;
+ int ret, val2;

switch (psp) {
case POWER_SUPPLY_PROP_TECHNOLOGY:
@@ -47,11 +47,18 @@ static int lego_ev3_battery_get_property(struct power_supply *psy,
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
/* battery voltage is iio channel * 2 + Vce of transistor */
- iio_read_channel_processed(batt->iio_v, &val->intval);
+ ret = iio_read_channel_processed(batt->iio_v, &val->intval);
+ if (ret)
+ return ret;
+
val->intval *= 2000;
val->intval += 200000;
+
/* plus adjust for shunt resistor drop */
- iio_read_channel_processed(batt->iio_i, &val2);
+ ret = iio_read_channel_processed(batt->iio_i, &val2);
+ if (ret)
+ return ret;
+
val2 *= 1000;
val2 /= 15;
val->intval += val2;
@@ -64,7 +71,10 @@ static int lego_ev3_battery_get_property(struct power_supply *psy,
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
/* battery current is iio channel / 15 / 0.05 ohms */
- iio_read_channel_processed(batt->iio_i, &val->intval);
+ ret = iio_read_channel_processed(batt->iio_i, &val->intval);
+ if (ret)
+ return ret;
+
val->intval *= 20000;
val->intval /= 15;
break;
--
2.17.1