A subset of smart battery commands return charge or energy depending on
the CAPACITY_MODE bit setting of BatteryMode(). In order to
unambiguously read a charge or energy value, it is necessary to ensure
that CAPACITY_MODE is set as desired, and not changed for the duration
of the attribute read.
Signed-off-by: Shawn Nematbakhsh <sha...@chromium.org>
---
drivers/power/supply/sbs-battery.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/power/supply/sbs-battery.c
b/drivers/power/supply/sbs-battery.c
index e3a114e60f1a..d7e68fd97099 100644
--- a/drivers/power/supply/sbs-battery.c
+++ b/drivers/power/supply/sbs-battery.c
@@ -171,6 +171,7 @@ struct sbs_info {
u32 i2c_retry_count;
u32 poll_retry_count;
struct delayed_work work;
+ struct mutex mode_lock;
};
static char model_name[I2C_SMBUS_BLOCK_MAX + 1];
@@ -623,7 +624,13 @@ static int sbs_get_property(struct power_supply *psy,
if (ret < 0)
break;
+ /* sbs_get_battery_capacity() will change the battery mode
+ * temporarily to read the requested attribute. Ensure we stay
+ * in the desired mode for the duration of the attribute read.
+ */
+ mutex_lock(&chip->mode_lock);
ret = sbs_get_battery_capacity(client, ret, psp, val);
+ mutex_unlock(&chip->mode_lock);
break;
case POWER_SUPPLY_PROP_SERIAL_NUMBER:
@@ -808,6 +815,7 @@ static int sbs_probe(struct i2c_client *client,
psy_cfg.of_node = client->dev.of_node;
psy_cfg.drv_data = chip;
chip->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
+ mutex_init(&chip->mode_lock);
/* use pdata if available, fall back to DT properties,
* or hardcoded defaults if not
--
2.13.1.508.gb3defc5cc-goog
