Protect the data using a mutex. Fix a race that can happen when
the user read from the sysfs and the worker execute in the middle.
Signed-off-by: Michael Trimarchi <
[hidden email]>
diff --git a/drivers/power/bq27000_battery.c b/drivers/power/bq27000_battery.c
index 01168ea..ddee537 100644
--- a/drivers/power/bq27000_battery.c
+++ b/drivers/power/bq27000_battery.c
@@ -134,6 +134,7 @@ struct bq27000_device_info {
struct bq27000_bat_regs regs;
};
+static DEFINE_MUTEX(battery_mutex);
static unsigned int cache_time = 5000;
module_param(cache_time, uint, 0644);
MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
@@ -210,11 +211,15 @@ static int bq27000_battery_get_property(struct power_supply *psy,
union power_supply_propval *val)
{
int n;
+ int ret = 0;
struct bq27000_device_info *di =
container_of(psy, struct bq27000_device_info, bat);
- if (di->regs.rsoc < 0 && psp != POWER_SUPPLY_PROP_PRESENT)
- return -ENODEV;
+ mutex_lock(&battery_mutex);
+ if (di->regs.rsoc < 0 && psp != POWER_SUPPLY_PROP_PRESENT) {
+ ret = -ENODEV;
+ goto out_unlock;
+ }
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
@@ -265,8 +270,10 @@ use_bat:
break;
}
/* power is actually going in or out... */
- if (di->regs.flags < 0)
- return di->regs.flags;
+ if (di->regs.flags < 0) {
+ ret = di->regs.flags;
+ goto out_unlock;
+ }
if (di->regs.flags & BQ27000_STATUS_CHGS)
val->intval = POWER_SUPPLY_STATUS_CHARGING;
else
@@ -275,36 +282,48 @@ use_bat:
case POWER_SUPPLY_PROP_HEALTH:
val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
/* Do we have accurate readings... */
- if (di->regs.flags < 0)
- return di->regs.flags;
+ if (di->regs.flags < 0) {
+ ret = di->regs.flags;
+ goto out_unlock;
+ }
if (di->regs.flags & BQ27000_STATUS_VDQ)
val->intval = POWER_SUPPLY_HEALTH_GOOD;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
- if (di->regs.volt < 0)
- return di->regs.volt;
+ if (di->regs.volt < 0) {
+ ret = di->regs.volt;
+ goto out_unlock;
+ }
/* mV -> uV */
val->intval = di->regs.volt * 1000;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
- if (di->regs.flags < 0)
- return di->regs.flags;
+ if (di->regs.flags < 0) {
+ ret = di->regs.flags;
+ goto out_unlock;
+ }
if (di->regs.flags & BQ27000_STATUS_CHGS)
n = -NANOVOLTS_UNIT;
else
n = NANOVOLTS_UNIT;
- if (di->regs.ai < 0)
- return di->regs.ai;
+ if (di->regs.ai < 0) {
+ ret = di->regs.ai;
+ goto out_unlock;
+ }
val->intval = (di->regs.ai * n) / di->pdata->rsense_mohms;
break;
case POWER_SUPPLY_PROP_CHARGE_FULL:
- if (di->regs.lmd < 0)
- return di->regs.lmd;
+ if (di->regs.lmd < 0) {
+ ret = di->regs.lmd;
+ goto out_unlock;
+ }
val->intval = (di->regs.lmd * 3570) / di->pdata->rsense_mohms;
break;
case POWER_SUPPLY_PROP_CHARGE_NOW:
- if (di->regs.nac < 0)
- return di->regs.nac;
+ if (di->regs.nac < 0) {
+ ret = di->regs.nac;
+ goto out_unlock;
+ }
val->intval = (di->regs.nac * 3570) / di->pdata->rsense_mohms;
break;
case POWER_SUPPLY_PROP_TEMP:
@@ -319,33 +338,44 @@ use_bat:
break;
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = di->regs.rsoc;
- if (val->intval < 0)
- return val->intval;
+ if (val->intval < 0) {
+ ret = val->intval;
+ goto out_unlock;
+ }
break;
case POWER_SUPPLY_PROP_PRESENT:
val->intval = !(di->regs.rsoc < 0);
break;
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
- if (di->regs.tte < 0)
- return di->regs.tte;
+ if (di->regs.tte < 0) {
+ ret = di->regs.tte;
+ goto out_unlock;
+ }
val->intval = 60 * di->regs.tte;
break;
case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
- if (di->regs.ttf < 0)
- return di->regs.ttf;
+ if (di->regs.ttf < 0) {
+ ret = di->regs.ttf;
+ goto out_unlock;
+ }
val->intval = 60 * di->regs.ttf;
break;
case POWER_SUPPLY_PROP_ONLINE:
if (di->pdata->get_charger_online_status)
val->intval = (di->pdata->get_charger_online_status)();
- else
- return -EINVAL;
+ else {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ break;
}
- return 0;
+out_unlock:
+ mutex_unlock(&battery_mutex);
+ return ret;
}
static void bq27000_battery_work(struct work_struct *work)
@@ -353,6 +383,8 @@ static void bq27000_battery_work(struct work_struct *work)
struct bq27000_device_info *di =
container_of(work, struct bq27000_device_info, work.work);
+ mutex_lock(&battery_mutex);
+
if ((di->pdata->hdq_initialized)()) {
struct bq27000_bat_regs regs;
@@ -375,6 +407,8 @@ static void bq27000_battery_work(struct work_struct *work)
if (!schedule_delayed_work(&di->work, cache_time))
dev_err(di->dev, "battery service reschedule failed\n");
+
+ mutex_unlock(&battery_mutex);
}
static enum power_supply_property bq27000_battery_props[] = {
