On Mon 2009-03-02 09:24:36, Oliver Neukum wrote: > Am Sonntag 01 März 2009 23:56:47 schrieb Pavel Machek: > > > Allowing user space to suspend input devices while they are still open > > > is useful. The user-space code that reads from the input devices does > > > not need to know if the device is suspended or not, and the kernel > > > cannot auto suspend input devices based on inactivity. > > > > Actually, I'd like you to fix your userspace and close input devices > > when it does not need them. Given the way you control the platform it > > should not be that hard. I do not see why we'd want to invent new > > interface for "uhuh, I have opened the keyboard but I am not really > > interested in keys being pressed". > > Generally you can't do this. A task has an open fd. > > - you cannot assume it can open the device again (fd may be > inherited) Well, those tasks that matter - X servers and similar - usually can. > - keeping the device open makes sure you are talking to the same device Well, you have to handle hotplug anyway, so... and the name will not change unless you unplug/replug. > - you may want to avoid repeating expensive initialisations That kind of initializations should perhaps be done at insmod, not open time? > - some input devices also do output I guess you want to separate those to two different devices, then. Anyway... * I'd prefer "close to powersave". I can see that can be tricky to use. So the alternative is * ioctl() "I'm not interested in exact keys, powersave" is something that makes sense. It should really be discussed with input people. I'd hate to see * magic /sys/.../file where you echo 1 to powersave. It is too disconnected from the input fd, and while it may make it easier to retrofit powermanagement without modifying Xservers etc... it will ultimately result in pretty ugly hacks. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
