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| author | Shawn Nematbakhsh <shawnn@chromium.org> | 2017-06-13 10:53:25 -0700 |
|---|---|---|
| committer | Sebastian Reichel <sre@kernel.org> | 2017-06-15 16:51:25 +0200 |
| commit | fe8a6534396807b8a0863cd146b72c0bce0b0c88 (patch) | |
| tree | cee4795b492c68ff19d5ab242ab48287d994f987 /drivers/power | |
| parent | 48f680c0a9cae36e37d91a3dc086143d6047c8a8 (diff) | |
| download | linux-fe8a6534396807b8a0863cd146b72c0bce0b0c88.tar.gz linux-fe8a6534396807b8a0863cd146b72c0bce0b0c88.tar.bz2 linux-fe8a6534396807b8a0863cd146b72c0bce0b0c88.zip | |
power: supply: sbs-battery: Prevent CAPACITY_MODE races
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 <shawnn@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Diffstat (limited to 'drivers/power')
| -rw-r--r-- | drivers/power/supply/sbs-battery.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c index cf43e38a9443..cdc1d71909a5 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]; @@ -622,7 +623,13 @@ 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: @@ -807,6 +814,7 @@ 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 |