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charger_manager: Don't use [delayed_]work_pending()

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There's no need to test whether a (delayed) work item in pending
before queueing, flushing or cancelling it.  Most uses are unnecessary
and quite a few of them are buggy.

Remove unnecessary pending tests and rewrite _setup_polling() so that
it uses mod_delayed_work() if the next polling interval is sooner than
currently scheduled.  queue_delayed_work() is used otherwise.

Only compile tested.  I noticed that two work items - setup_polling
and cm_monitor_work - schedule each other.  It's a very unusual
construct and I'm fairly sure it's racy.  You can't break such
circular dependency by calling cancel on each.  I strongly recommend
revising the mechanism.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Donggeun Kim <dg77.kim@samsung.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
This commit is contained in:
Tejun Heo 2012-12-21 17:56:51 -08:00 committed by Anton Vorontsov
parent 41468a1119
commit 2fbb520d20
1 changed files with 16 additions and 15 deletions
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23
drivers/power/charger-manager.c
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@ -669,15 +669,21 @@ static void _setup_polling(struct work_struct *work)
WARN(cm_wq == NULL, "charger-manager: workqueue not initialized"
". try it later. %s\n", __func__);
/*
* Use mod_delayed_work() iff the next polling interval should
* occur before the currently scheduled one. If @cm_monitor_work
* isn't active, the end result is the same, so no need to worry
* about stale @next_polling.
*/
_next_polling = jiffies + polling_jiffy;
if (!delayed_work_pending(&cm_monitor_work) ||
(delayed_work_pending(&cm_monitor_work) &&
time_after(next_polling, _next_polling))) {
next_polling = jiffies + polling_jiffy;
if (time_before(_next_polling, next_polling)) {
mod_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
next_polling = _next_polling;
} else {
if (queue_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy))
next_polling = _next_polling;
}
out:
mutex_unlock(&cm_list_mtx);
}
@ -751,8 +757,7 @@ static void misc_event_handler(struct charger_manager *cm,
if (cm_suspended)
device_set_wakeup_capable(cm->dev, true);
if (!delayed_work_pending(&cm_monitor_work) &&
is_polling_required(cm) && cm->desc->polling_interval_ms)
if (is_polling_required(cm) && cm->desc->polling_interval_ms)
schedule_work(&setup_polling);
uevent_notify(cm, default_event_names[type]);
}
@ -1170,7 +1175,6 @@ static int charger_extcon_notifier(struct notifier_block *self,
* when charger cable is attached.
*/
if (cable->attached && is_polling_required(cable->cm)) {
if (work_pending(&setup_polling))
cancel_work_sync(&setup_polling);
schedule_work(&setup_polling);
}
@ -1718,9 +1722,7 @@ static int charger_manager_remove(struct platform_device *pdev)
list_del(&cm->entry);
mutex_unlock(&cm_list_mtx);
if (work_pending(&setup_polling))
cancel_work_sync(&setup_polling);
if (delayed_work_pending(&cm_monitor_work))
cancel_delayed_work_sync(&cm_monitor_work);
for (i = 0 ; i < desc->num_charger_regulators ; i++) {
@ -1790,7 +1792,6 @@ static int cm_suspend_prepare(struct device *dev)
cm_suspended = true;
}
if (delayed_work_pending(&cm->fullbatt_vchk_work))
cancel_delayed_work(&cm->fullbatt_vchk_work);
cm->status_save_ext_pwr_inserted = is_ext_pwr_online(cm);
cm->status_save_batt = is_batt_present(cm);