@@ -1801,7 +1801,7 @@ static void bq27xxx_battery_update_unlocked(struct bq27xxx_device_info *di)
di->last_update = jiffies;
- if (poll_interval > 0)
+ if (!di->removed && poll_interval > 0)
mod_delayed_work(system_wq, &di->work, poll_interval * HZ);
}
@@ -2132,22 +2132,18 @@ EXPORT_SYMBOL_GPL(bq27xxx_battery_setup);
void bq27xxx_battery_teardown(struct bq27xxx_device_info *di)
{
- /*
- * power_supply_unregister call bq27xxx_battery_get_property which
- * call bq27xxx_battery_poll.
- * Make sure that bq27xxx_battery_poll will not call
- * schedule_delayed_work again after unregister (which cause OOPS).
- */
- poll_interval = 0;
-
- cancel_delayed_work_sync(&di->work);
-
- power_supply_unregister(di->bat);
-
mutex_lock(&bq27xxx_list_lock);
list_del(&di->list);
mutex_unlock(&bq27xxx_list_lock);
+ /* Set removed to avoid bq27xxx_battery_update() re-queuing the work */
+ mutex_lock(&di->lock);
+ di->removed = true;
+ mutex_unlock(&di->lock);
+
+ cancel_delayed_work_sync(&di->work);
+
+ power_supply_unregister(di->bat);
mutex_destroy(&di->lock);
}
EXPORT_SYMBOL_GPL(bq27xxx_battery_teardown);
@@ -68,6 +68,7 @@ struct bq27xxx_device_info {
struct bq27xxx_access_methods bus;
struct bq27xxx_reg_cache cache;
int charge_design_full;
+ bool removed;
unsigned long last_update;
struct delayed_work work;
struct power_supply *bat;
Before this patch bq27xxx_battery_teardown() was setting poll_interval = 0 to avoid bq27xxx_battery_update() requeuing the delayed_work item. There are 2 problems with this: 1. If the driver is unbound through sysfs, rather then the module being rmmod-ed, this changes poll_interval unexpectedly 2. This is racy, after it being set poll_interval could be changed before bq27xxx_battery_update() checks it through /sys/module/bq27xxx_battery/parameters/poll_interval Fix this by added a removed attribute to struct bq27xxx_device_info and using that instead of setting poll_interval to 0. There also is another poll_interval related race on remove(), writing /sys/module/bq27xxx_battery/parameters/poll_interval will requeue the delayed_work item for all devices on the bq27xxx_battery_devices list and the device being removed was only removed from that list after cancelling the delayed_work item. Fix this by moving the removal from the bq27xxx_battery_devices list to before cancelling the delayed_work item. Fixes: 8cfaaa811894 ("bq27x00_battery: Fix OOPS caused by unregistring bq27x00 driver") Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/power/supply/bq27xxx_battery.c | 22 +++++++++------------- include/linux/power/bq27xxx_battery.h | 1 + 2 files changed, 10 insertions(+), 13 deletions(-)