Re: [PATCH] thermal: core: Send a sysfs notification on trip points

[Vincent Whitchurch]

On Fri, Apr 03, 2020 at 05:26:39PM +0200, Daniel Lezcano wrote:
> On 03/04/2020 16:40, Vincent Whitchurch wrote:
> > Normally sysfs_notify() is used to notify userspace that the value
> > of the sysfs file has changed, but in this case it's being used on
> > a sysfs file whose value never changes.  I don't know if there are
> > other drivers that do something similar.
> 
> I think so:
> 
> eg.
> 
> drivers/hwmon/adt7x10.c:
> 	sysfs_notify(&dev->kobj, NULL, "temp1_max_alarm");
> drivers/hwmon/adt7x10.c:
> 	sysfs_notify(&dev->kobj, NULL, "temp1_min_alarm");
> drivers/hwmon/adt7x10.c:
> 	sysfs_notify(&dev->kobj, NULL, "temp1_crit_alarm");
> 
> drivers/hwmon/abx500.c:
> 	sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
> drivers/hwmon/abx500.c:
> 	sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
> 
> drivers/hwmon/stts751.c:
> 	sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm");
> drivers/hwmon/stts751.c:
> 	sysfs_notify(&priv->dev->kobj, NULL, "temp1_min_alarm");
> 
> There are also some other places I believe they are doing the same like:
> 
> drivers/md/md.c:
> 	sysfs_notify(&mddev->kobj, NULL, "sync_completed");
> drivers/md/md.c:
> 	sysfs_notify(&mddev->kobj, NULL, "degraded");

AFAICS all these drivers (including the hwmon ones) use sysfs_notify()
to notify that the value of the sysfs file has changed, unlike your
proposed patch.