From 5993b9887ac3b80fba78e1a488ac748d6e4429c1 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Wed, 29 Jun 2022 08:26:20 -0700 Subject: hwmon: (lm90) Use worker for alarm notifications Reporting alarms using hwmon_notify_event() may result in a callback from the thermal subsystem. This means that such notifications must not hold the update lock to avoid a deadlock. To avoid this situation, use a worker to handle notifications. Reported-by: Dmitry Osipenko Tested-by: Dmitry Osipenko Fixes: f6d0775119fb ("hwmon: (lm90) Rework alarm/status handling") Signed-off-by: Guenter Roeck --- drivers/hwmon/lm90.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'drivers/hwmon') diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index 9d878163a1f2..03d07da8c2dc 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -693,6 +693,7 @@ struct lm90_data { struct hwmon_chip_info chip; struct mutex update_lock; struct delayed_work alert_work; + struct work_struct report_work; bool valid; /* true if register values are valid */ bool alarms_valid; /* true if status register values are valid */ unsigned long last_updated; /* in jiffies */ @@ -1043,13 +1044,18 @@ static int lm90_update_limits(struct device *dev) return 0; } -static void lm90_report_alarms(struct device *dev, struct lm90_data *data) +static void lm90_report_alarms(struct work_struct *work) { - u16 cleared_alarms = data->reported_alarms & ~data->current_alarms; - u16 new_alarms = data->current_alarms & ~data->reported_alarms; + struct lm90_data *data = container_of(work, struct lm90_data, report_work); + u16 cleared_alarms, new_alarms, current_alarms; struct device *hwmon_dev = data->hwmon_dev; + struct device *dev = &data->client->dev; int st, st2; + current_alarms = data->current_alarms; + cleared_alarms = data->reported_alarms & ~current_alarms; + new_alarms = current_alarms & ~data->reported_alarms; + if (!cleared_alarms && !new_alarms) return; @@ -1101,7 +1107,7 @@ static void lm90_report_alarms(struct device *dev, struct lm90_data *data) if (st2 & MAX6696_STATUS2_R2OT2) hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_emergency_alarm, 2); - data->reported_alarms = data->current_alarms; + data->reported_alarms = current_alarms; } static int lm90_update_alarms_locked(struct lm90_data *data, bool force) @@ -1143,7 +1149,7 @@ static int lm90_update_alarms_locked(struct lm90_data *data, bool force) (data->config & 0x80); if (force || check_enable) - lm90_report_alarms(&client->dev, data); + schedule_work(&data->report_work); /* * Re-enable ALERT# output if it was originally enabled, relevant @@ -2552,6 +2558,7 @@ static void lm90_restore_conf(void *_data) struct i2c_client *client = data->client; cancel_delayed_work_sync(&data->alert_work); + cancel_work_sync(&data->report_work); /* Restore initial configuration */ if (data->flags & LM90_HAVE_CONVRATE) @@ -2769,6 +2776,7 @@ static int lm90_probe(struct i2c_client *client) i2c_set_clientdata(client, data); mutex_init(&data->update_lock); INIT_DELAYED_WORK(&data->alert_work, lm90_alert_work); + INIT_WORK(&data->report_work, lm90_report_alarms); /* Set the device type */ if (client->dev.of_node) -- cgit v1.2.3