[Dev] [Tzivi] Multi-seat/multi-user setup in IVI: Questions

Kaskinen, Tanu tanu.kaskinen at intel.com
Wed Aug 27 14:36:44 GMT 2014

On Wed, 2014-08-27 at 13:57 +0000, Zaman, Imran wrote:
> Hi,
> We are trying to setup multi-seat on IVI box VTC1010. We manage to
> setup two seats (seat0, and seat1) using tlm (and some modifications
> to udev rules file for seat; please see end of email). 
> In this context, we came across couple of questions:
> 1- Who should be "master of seat" as it is mandatory? we have set
> usb-hub as master-of-seat.

My relatively uneducated answer is that any device that is always
present when the seat is present is fine. Instead of a specific usb hub,
I'd assign the usb port on VTC1010 that you have dedicated for the hub
as the master, because that way the configuration can be reused on any
VTC1010 (it seems that the udev rules that you use are specific to
certain usb hub models, so the rules are useful only on your system).
Note that I don't know for sure that the individual ports show up as
distinct devices in udev. If they don't, then my suggestion won't work.

> 2- How could separate monitor be attached to a seat (as one is
> connected on VGA and other on DP)? we have done that using weston.ini
> but it does not seem to work.

What do you mean by "does not seem to work"? logind certainly won't know
anything about the assignments you do in weston.ini, but is that a

Perhaps you already knew this, but currently udev doesn't support
assigning different outputs of one GPU to different seats (this is a
driver limitation, as the drivers don't provide separate devices for
those outputs). This should not be a problem, though, if weston allows
you to manually specify the seats in weston.ini.

I'd suggest adding a udev rule that prevents the GPU from being assigned
to any seat, since it's shared by two seats. Instructions for that can
be found here:


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