On Mon, 2009-12-07 at 20:22 -0800, Dmitry Torokhov wrote: > On Sun, Dec 06, 2009 at 09:47:04AM +0100, Pavel Machek wrote: > > Hi! > > > > > > > But runtime-pm.txt says for example: > > > > > > Generally, remote wake-up should be enabled for all input devices > > > put into a low power state at run time. > > > > > > But in this case the requirement is to suppress input events from a > > > given device, effectively muting and putting it into low power state, > > > even though it's still open by some other parties. Runtime PM, on the > > > other hand tries not to interfere with the normal usage of the device. > > > > > > Later: > > > > > > (3) ->runtime_idle() and ->runtime_suspend() can only be executed for a > > > device the usage counter of which is equal to zero _and_ [...] > > > > > > which underlines the difference again: the usage counter (defined by > > > common sense) won't be zero in our case, because the device is > > > constantly kept open, while we want to mute it, putting it into a low > > > power state. > > ... > > > Actually, this could be implemented by the various users cooperating in > > > closing the device, letting it go to sleep automatically. But this > > > requires strictly cooperating parties and is more complicated that > > > flipping some master switch of the device. We're looking for this > > > master switch, before needlessly building our own. > > > > Please just close the device properly. I do not think we want 100 > > different 'please mute keys A and G', 'please mute middle mouse button', > > ... interfaces anywhere near mainline. > > > > I do not think it is practical to simply close the device, given that > there may be several applications that have it open. I constantly see > embedded guys adding custom knobs to the devices allowing them to shut > off the device when not in use. Kind of runtame PM but user-initiated. > > I would really love to have it implemented in the driver core so the > interface is the same for all drivers (that support this future). > > > Or just do it as local patch. > > I also see that gpio-keys is quite different in the sence that it can > shut off buttons selectively. I fact, at the moment every button can be > considered a separate device... But that would be too much overhead. > > They could probably split the keys into 2 groups (critical that should > be always active) and not critical, that could be shut off, but I think > they want teh flexibility of controlling this at runtime instead of > doing it in board data. I suggested including this into the "abstract input device" model, but you refuse this. But I still think it is a good idea. Indeed, if we look at an input device as at something abstract which has many keys, why we cannot assume that separate keys can be enabled/disabled? Just imagine you have a very advanced keybord :-) And we simply implement an ioctl which enables/disables a specific key. The generic layers just pass this ioctl down to the lower lever drivers. If the specific input device or driver support it - fine, if not - it returns -EINVAL or something like that. -- Best Regards, Artem Bityutskiy (Артём Битюцкий) _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
