Re: 'Phys:' field for keyboards (and other input devices)

[Vojtech P. <vo...@su...>]

On Fri, Sep 27, 2002 at 10:55:45AM +0200, Andreas Schuldei wrote:

> * Vojtech Pavlik (vo...@su...) [020927 09:54]:
> > > it is important to bind Keyboards to VTs to be able to start
> > > Xservers on that VT. Mice (for X) can be configured in the
> > > XF86Config. but it would perhaps be nice to be able to configure
> > > which mouse goes with which /dev/input/mouse* device, which in
> > > turn get used in the XF86Config. Do people agree on this or is
> > > that unneeded featureism?
> > 
> > No, X should be taught to open the correct /dev/input/event* device (not
> > mouse*), based on a phys (or ID or ...) entry given in XF86Config.
> 
> And that is because the /dev/input/event* is the thing of the
> future and mouse* will pass away? 

Correct.

> But my point was really to have a way to determine/configure
> which mouse would become mouse0 (or even event0, if you please)
> instead of mouse3, etc.

There is a way to determine what event0 is (EVIOCGPHYS), or to find out
what a certain mouse has become (/proc/bus/input/devices).

As to the device number assignment, it's not sanely possible to do with
hotplug, etc. The minor numbers will simply have to stay more or less
random.

> the point in that would be to have 
> - a more tidy XF86Config, where the Xserver :0 connects to the
>   mouse0 etc (this point is minor and rather cosmetic)

If you really need it, you can make a hotplug agent that'll rename or
link or mknod the correct mouse device (based on major/minor) to
/dev/mouse0.

> - a way that a given mouse model remains the dedicated poninting
>   device of a given (configured) Xserver, even after plugging and
>   unplugging of your devices, in which the initialisiation order
>   (and device/event number) might change as of now.
>   This is actually the same as for the keyboards.

This I fear needs to have support in Xserver. For example an userspace
app called by the hotplug agent that'll connect to Xserver and via some
X-extension tell it about what happened to hotpluggable mice.

> Right now i am putting together a system which (among other) uses
> a userspace mechanism to determine the vt which it should bind
> keyboards to. for conveniance i am useing the hotplug interface
> and consider extending hotplug to return vt numbers. 
> 
> I would like to get feedback from someone more involved in these
> matters. who could help me?

Me, Greg KH and Pat Mochel.

-- 
Vojtech Pavlik
SuSE Labs