@@ -1761,7 +1761,7 @@ static int bq27xxx_battery_read_health(struct bq27xxx_device_info *di)
return POWER_SUPPLY_HEALTH_GOOD;
}
-void bq27xxx_battery_update(struct bq27xxx_device_info *di)
+static void bq27xxx_battery_update_unlocked(struct bq27xxx_device_info *di)
{
struct bq27xxx_reg_cache cache = {0, };
bool has_singe_flag = di->opts & BQ27XXX_O_ZERO;
@@ -1800,6 +1800,16 @@ void bq27xxx_battery_update(struct bq27xxx_device_info *di)
di->cache = cache;
di->last_update = jiffies;
+
+ if (poll_interval > 0)
+ mod_delayed_work(system_wq, &di->work, poll_interval * HZ);
+}
+
+void bq27xxx_battery_update(struct bq27xxx_device_info *di)
+{
+ mutex_lock(&di->lock);
+ bq27xxx_battery_update_unlocked(di);
+ mutex_unlock(&di->lock);
}
EXPORT_SYMBOL_GPL(bq27xxx_battery_update);
@@ -1810,9 +1820,6 @@ static void bq27xxx_battery_poll(struct work_struct *work)
work.work);
bq27xxx_battery_update(di);
-
- if (poll_interval > 0)
- schedule_delayed_work(&di->work, poll_interval * HZ);
}
static bool bq27xxx_battery_is_full(struct bq27xxx_device_info *di, int flags)
@@ -1985,10 +1992,8 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
struct bq27xxx_device_info *di = power_supply_get_drvdata(psy);
mutex_lock(&di->lock);
- if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
- cancel_delayed_work_sync(&di->work);
- bq27xxx_battery_poll(&di->work.work);
- }
+ if (time_is_before_jiffies(di->last_update + 5 * HZ))
+ bq27xxx_battery_update_unlocked(di);
mutex_unlock(&di->lock);
if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
bq27xxx_battery_update() assumes / requires that it is only run once, not multiple times at the same time. But there are 3 possible callers: 1. bq27xxx_battery_poll() delayed_work item handler 2. bq27xxx_battery_irq_handler_thread() I2C IRQ handler 3. bq27xxx_battery_setup() And there is no protection against these racing with each other, fix this race condition by making all callers take di->lock: - Rename bq27xxx_battery_update() to bq27xxx_battery_update_unlocked() - Add new bq27xxx_battery_update() which takes di->lock and then calls bq27xxx_battery_update_unlocked() - Make stale cache check code in bq27xxx_battery_get_property(), which already takes di->lock directly to check the jiffies, call bq27xxx_battery_update_unlocked() instead of messing with the delayed_work item - Make bq27xxx_battery_update_unlocked() mod the delayed-work item so that the next poll is delayed to poll_interval milliseconds after the last update independent of the source of the update Fixes: 740b755a3b34 ("bq27x00: Poll battery state") Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/power/supply/bq27xxx_battery.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)