On Tue, 2014-11-11 at 16:46 +0100, Lennart Poettering wrote: > On Wed, 29.10.14 15:45, Bastien Nocera (had...@hadess.net) wrote: > > > For a very specific definition of inactive. > > > > I'm looking at a way for the iio-sensor-proxy at: > > https://github.com/hadess/iio-sensor-proxy > > to suspend reading from accelerometers (or maybe to turn them off), when > > all the sessions are locked and the screens turned off. > > > > This would usually mean that I would enable reading from the sensor if > > one session is "active" and stop reading if none are "active". Is this > > correct? Is it up to the session manager (eg. gnome-session) to tell us > > whether a session is active or not, or do I have this backwards? > > logind knows when sessions are active and not. > > Note that access control to such devices should really not be > per-session, but per-user. Meaning that a user should get access to > the device as long as he has at least one session active. > > That said, I am not sure I really grok what iio-sensor-proxy is doing, > and whether doing it involving both uinput and uevents is really such > a great idea. > > I am tempted to say that we should probably add support for the > orientation sensors to logind, and abstract them away in logind so > that only simple high-level rotation change events are sent > out.
Which is already what the code in the iio-sensor-proxy tries to do. iio-sensor-proxy's code means that we can have an accelerometer device showing up in udev, with the orientation updated only when the orientation of the device changes in a major way. > I am pretty sure that orientation is something pretty much all > desktop environments really want to know about, and as logind is > really a system service these days that only exists for the purpose of > making writing of desktop environments easy I think adding the > orientation stuff to logind wouldn't be too far off. And I figure we > need it for the userspace console too in one way or > another... Orientation is pretty much a property of a "seat" anyway, > and I figure it should be exposed as one, too. It's not a seat property. It's a property of the display itself. If you connected a tablet to a TV and rotated the tablet, you're not rotating the TV as well. > Also, we really should > figure out a logic where the desktop subscribes to orientation changes > and we only in that case even do the IIO access, rather than pushing > the IIO events up the stack even when nobody is listening. Which is what my original request was all about. > I am willing to take a patch for this, but then again, as I own a Yoga > I might look into this myself too one day. I need to figure out how to make the IIO code not suck first though. Cheers _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel