Target Display Mode in Fedora

[David Airlie]

> The iMac and HP Z1 have a bi-directional DisplayPort/Thunderbolt port, which
> lets them be used as a Display for another computer. Apple calls it Target
> Display Mode, though HP doesn't seem to have a special name for it. This is
> really quite useful, I've used an iMac hooked up to a Linux machine at a
> previous job, and it's awesome to switch between the two machines when
> you've only got space for one display on the desk. The feature is invoked by
> a fairly non-standard keyboard combination. Here is a video illustrating
> what I mean (
> http://www.youtube.com/watch?feature=player_detailpage&v=Y7_OZgBX8kQ#t=60 ),
> note how he switches the iMac from being the display for the MacBook to
> being an iMac again via keyboard shortcut (sort of off-screen).
> 
> However, this feature is only implemented in OS X and Windows (via HP's My
> Display application) on the iMac and Z1 respectively. Which means that if,
> for example, a Z1 has Linux as the primary OS, the Z1 cannot currently be
> used as a monitor for a laptop or another computer (via Target Display
> Mode). As far as I've been able to discover, Target Display Mode does not
> exist under any flavor of Linux.
> 
> What would it take to support this in Fedora? Is this a Desktop-centric
> feature for Gnome/KDE/Cinnamon, or is this something that would/should be
> part of the Linux kernel itself? I don't think it's directly part of a
> graphics driver (at least on Windows, since HP released My Display as a
> separate program), but again I'm not sure.

You'd have to reverse engineer or ask HP/Apple what they actually do for this
to work.

then implement that.

Dave.