I'm using Linux with a 3.9 kernel (BohdiLinux, but I'm looking for a distro (or at least desktop environment) agnostic answer).
Something is periodically (or on some event, perhaps) reseting the backlight level of my screen laptop, and I would like to know what process it is.
I naivly try to watch acess on /sys/class/backlight with inotifywatch, but events on /sys does not seems to be recorded.
I also try to see if there was some acpi events, but nothing was recorded by acpi_listen when the reset occures.
I have no idea of the process doing the reset, or even if it is always started or started on demand by another one, so I don't see how I could use lsof.
How could I progress from here ? Thanks for any advice !
- it seems that sysfs can not be monitored: http://email@example.com/msg07648.html
- udevadm confirms that what is reseting the brightness is a sysfs event, but I still don't know how to find what is triggering that udev event
 actual command: sudo inotifywatch -r -v /sys/class/backlight/
 actual command: sudo acpi_listen
% sudo udevadm monitor --udev --property monitor will print the received events for: UDEV - the event which udev sends out after rule processing UDEV [27661.753446] change /devices/pci0000:00/0000:00:02.0/backlight/acpi_video1 (backlight) ACTION=change DEVPATH=/devices/pci0000:00/0000:00:02.0/backlight/acpi_video1 SEQNUM=6027 SOURCE=sysfs SUBSYSTEM=backlight UDEV_LOG=7 USEC_INITIALIZED=27661753199