Commit 2fbb520d authored by Tejun Heo's avatar Tejun Heo Committed by Anton Vorontsov
Browse files

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



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: default avatarTejun 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: default avatarAnton Vorontsov <anton.vorontsov@linaro.org>
parent 41468a11

drivers/power/charger-manager.c

+16 −15
Original line number Diff line number Diff line
@@ -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);

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