Re: [RFC PATCH] PM / Runtime: runtime: Add sysfs option for forcing runtime suspend

From: Alan Stern
Date: Mon Sep 21 2015 - 10:38:52 EST


On Mon, 21 Sep 2015, Pavel Machek wrote:

> > > In fact, then, what you need seems to be the feature discussed by Alan
> > > and me some time ago allowing remote wakeup do be disabled for runtime
> > > PM from user space as that in combination with autosuspend should
> > > address your use case.
> >
> > That, plus they want the touchscreen to go into runtime suspend
> > whenever the screen is off (was this not the main reason for the
> > patch?).
> >
> > It seems to me that it should be possible to arrange for this to happen
> > simply by making userspace close the touchscreen device when the screen
> > is turned off. Or am I missing something?
>
> Well... that's not what existing userspace expects. Your X windows
> server will not close the touchscreen.

Surely that's a userspace issue, rather than a kernel problem? The X
server does have some notion of power management and power savings; why
not extend that notion to include touchscreens?

> ..and it would be nice to have enough hardware abstraction in the
> kernel so that X can be used on phones...

What -- not Wayland?! :-)

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/