Messages in this thread |  | | | Date | Mon, 2 Mar 2009 15:34:22 +0100 | | From | Pavel Machek <> | | Subject | Re: [RFD] Automatic suspend |
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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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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