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authorShawn Nematbakhsh <shawnn@chromium.org>2017-06-13 20:53:25 +0300
committerSebastian Reichel <sre@kernel.org>2017-06-15 17:51:25 +0300
commitfe8a6534396807b8a0863cd146b72c0bce0b0c88 (patch)
treecee4795b492c68ff19d5ab242ab48287d994f987 /drivers/power/supply/sbs-battery.c
parent48f680c0a9cae36e37d91a3dc086143d6047c8a8 (diff)
downloadlinux-fe8a6534396807b8a0863cd146b72c0bce0b0c88.tar.xz
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/supply/sbs-battery.c')
-rw-r--r--drivers/power/supply/sbs-battery.c8
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