Hi, On 25-11-16 11:01, Pavel Machek wrote: > Hi! > >> In view of the above we could report hw brightness changes with POLLPRI >> on brightness file, but unfortunately we can't because it is impossible >> to guarantee that readout of brightness file will return the brightness >> the POLLPRI was meant to notify about. > > Agreed here. > >> That's why a separate read only file seems to be the only proper >> solution. > > Yes please. And lets make self-changing leds into a trigger, as > proposed, and as Hans' patch should be already doing. > >> Moreover, the file should return the brightness from the time >> of last POLLPRI. > > Not sure I agree here. Normally, kernel returns current state for > variables, does not track "old" state.
Agreed, storing the last state just unnecessarily complicates things. So do we have a consensus on implementing a new hw_brightness_change sysfs attribute now, which only some LEDs will have, can be polled to detect changed done autonomously by the hardware and returns the current / actual LED brightness when read ? As for the modeling how the hotkey controls the LED as a trigger, although I do like this from one pov, I can see Jacek's point that this is confusing as there really is nothing to configure here, where as normally a user could do "echo none > trigger" to break the link. So I think that is best (cleanest /minimal non confusing API) with just the hw_brightness_change sysfs-attribute and not model this as a trigger. That, or fall back to my latest patch-set as posted, I still like that one the most. Regards, Hans ------------------------------------------------------------------------------ _______________________________________________ ibm-acpi-devel mailing list ibm-acpi-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ibm-acpi-devel
