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: 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>
diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 029732d..8acc3f8 100644
--- a/drivers/power/charger-manager.c
+++ b/drivers/power/charger-manager.c
@@ -669,15 +669,21 @@
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 @@
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]);
}
@@ -1170,8 +1175,7 @@
* when charger cable is attached.
*/
if (cable->attached && is_polling_required(cable->cm)) {
- if (work_pending(&setup_polling))
- cancel_work_sync(&setup_polling);
+ cancel_work_sync(&setup_polling);
schedule_work(&setup_polling);
}
@@ -1718,10 +1722,8 @@
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);
+ cancel_work_sync(&setup_polling);
+ cancel_delayed_work_sync(&cm_monitor_work);
for (i = 0 ; i < desc->num_charger_regulators ; i++) {
struct charger_regulator *charger
@@ -1790,8 +1792,7 @@
cm_suspended = true;
}
- if (delayed_work_pending(&cm->fullbatt_vchk_work))
- cancel_delayed_work(&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);