[Libdlo] Linux DispayLink issues
martin at decky.cz
Tue Mar 15 07:34:57 PDT 2011
> In case of wireless USB, device connection is more complicated task then
> in usual USB. So we want be able to connect wireless USB video card to
> host while X server is running.
Yes, sure. And this is exactly the use case which is not supported by
the current X server. Linux kernel will recognize the new USB video card
on connection, you can even start a new instance of the X server on it,
but there is no way how to "plug" it into the running instance of the X
> Is it possible to implement special x-driver which will care about plug
> and play issue of USB/wireless USB connected video cards?
Technically, yes. Such "wrapper" driver might be a slightly better
solution than all the current approaches, it might even allow to do such
"tricks" with the DisplayLink devices which are currently only possible
in Windows (like using the power of the primary GPU(s) for 3D
acceleration of the DisplayLink output).
But it will also introduce some overhead even in the case there is no DL
I think, for the long run, it is simply needed to improve the core X
server to allow much higher degree of run-time (re)configuration. I
don't want to be a fault-finder, but it's really a shame that the X
server cannot change the BPP while running. 15 years since Windows can
do it quite reliably ..
BTW: Some two three years ago people were talking about a future version
of XRandR (1.4 or something) which should bring multi-GPU support and
such stuff. Does anybody know what is the current status of these great
More information about the Libdlo