evie/android_kernel_oneplus_msm8998
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drivers: thermal: Exit sysfs notify kthread when sensor unregisters

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When a thermal zone unregisters, it initiates a blocking call
kthread_stop for the sysfs notify kthread to exit. But the sysfs notify
kthread is blocked on a completion event, which may not be triggered after
the sensor driver initiates a thermal zone unregister call. So, the
kthread_stop will be blocked forever.

As a part of thermal zone unregister, set a thermal zone unregister flag
and send a completion event before calling kthread_stop. Make the sysfs
notify kthread to be aware of thermal zone unregister flag and exit
after the completion event is triggered.

Change-Id: Icf045e0ad6e28135cd3a54c15d9923f095a286ff
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>
This commit is contained in:
Ram Chandrasekar 2017-02-10 14:58:30 -07:00
parent 487ff740cb
commit 4a86c2f3cc
2 changed files with 10 additions and 4 deletions
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13
drivers/thermal/thermal_core.c
View file

@ -4,7 +4,7 @@
* Copyright (C) 2008 Intel Corp
* Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
* Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
@ -382,9 +382,11 @@ static __ref int sensor_sysfs_notify(void *data)
struct sensor_info *sensor = (struct sensor_info *)data;
while (!kthread_should_stop()) {
while (wait_for_completion_interruptible(
&sensor->sysfs_notify_complete) != 0)
;
if (wait_for_completion_interruptible(
&sensor->sysfs_notify_complete) != 0)
continue;
if (sensor->deregister_active)
return ret;
reinit_completion(&sensor->sysfs_notify_complete);
sysfs_notify(&sensor->tz->device.kobj, NULL,
THERMAL_UEVENT_DATA);
@ -580,6 +582,7 @@ int sensor_init(struct thermal_zone_device *tz)
sensor->threshold_max = INT_MAX;
sensor->max_idx = -1;
sensor->min_idx = -1;
sensor->deregister_active = false;
mutex_init(&sensor->lock);
INIT_LIST_HEAD_RCU(&sensor->sensor_list);
INIT_LIST_HEAD_RCU(&sensor->threshold_list);
@ -2471,6 +2474,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
thermal_remove_hwmon_sysfs(tz);
flush_work(&tz->sensor.work);
tz->sensor.deregister_active = true;
complete(&tz->sensor.sysfs_notify_complete);
kthread_stop(tz->sensor.sysfs_notify_thread);
mutex_lock(&thermal_list_lock);
list_del_rcu(&tz->sensor.sensor_list);

1
include/linux/thermal.h
View file

@ -178,6 +178,7 @@ struct sensor_info {
struct work_struct work;
struct task_struct *sysfs_notify_thread;
struct completion sysfs_notify_complete;
bool deregister_active;
};
/**