Messages in this thread | | | Subject | Re: [PATCH] thermal: core: Send a sysfs notification on trip points | From | Daniel Lezcano <> | Date | Mon, 6 Apr 2020 11:45:10 +0200 |
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On 06/04/2020 09:45, Vincent Whitchurch wrote: > 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.
Sorry, I don't have the same understanding:
drivers/hwmon/adt7x10.c:
- receives an interrupt because one of the programmed temperature is reached - reads the status to know which one and sends a sysfs notification
drivers/hwmon/stts751.c:
- receives an I2C alert message, checks if it is a temperature alert and then sends a sysfs notification
drivers/hwmon/abx500:
- This one is probably sending a notification on a change
The documentation also is giving the semantic for sysfs_notify for certain sysfs nodes:
Documentation/misc-devices/apds990x.txt: sysfs_notify called when threshold interrupt occurs Documentation/misc-devices/bh1770glc.txt: sysfs_notify called when threshold interrupt occurs
AFAICT, it is a matter of documenting the notification for trip_point_*_temp.
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