[elrepo] package suggestion: USB DisplayLink drivers and X11 driver

[Covert]

  On 6/9/11 4:08 PM, Phil Perry wrote:
>
> Hi Greg,
>
> This certainly sounds interesting and like a candidate for elrepo.
> You've done a great job of "selling" it to me :-)
>
> I have a couple questions that I'm hoping you might be able to help with.
>
> Are you thinking el5, el6 or both?
>
> I've had a very quick look around the above wiki site. There are a
> couple "kernel" driver branches available - the udlfb.ko driver in the
> mainline kernel which we could backport and the displaylink-mod listed
> on the above wiki. Which did you have in mind, and why? I'm guessing we
> would prefer to backport the official kernel driver as that's the only
> one ever likely to end up officially supported in RHEL.
>
> Can you point me to the X11 drivers we should be looking at please.
>
> Have you actually managed to build any of this on el6 and get it
> working? If so, that would be an immense help.
>
> If we build packages, can you help with testing them? We don't have the
> necessary hardware which always makes it difficult.
>
> Regards,
>
> Phil
Hi Phil,

Glad it piqued your interest!  I currently run SL6, so I would be most 
interested in EL6 drivers, but for the use case above, I think it would 
be easily useful for EL5.

This page gives a very step by step set of instructions for enabling the 
"plug a whole console into a server" scenario for EL6:  
http://otb.bg/blog/usb-multiseat-on-red-hat-enterprise-linux-6/252

They call it "multiseat", but really a keyboard, mouse, and usb video 
card all attached to a single USB hub plugged into a server, where an 
GDM and Xorg are started up dynamically when you attach the hub.  The 
most complicated part of these instructions is actually that the version 
of GDM in EL6 is too new -- the technique they describe uses a feature 
that was removed from recent versions, but actually in EL5 (which is why 
I said that EL5 would be handy.)

Now, here's where I make a little confession.  :)  I used that use case 
as I thought it would be most interesting to this audience, but I 
actually want to use these drivers to extend my desktop over to an extra 
monitor I have on my desk.  I have one of these really neat little 
monitors:  http://www.thinkgeek.com/computing/usb-gadgets/bfa3/

I have several machines plugged into a USB-DVI KVM.  I can switch 
between macs, windows, and linux machines, and when I switch to them 
(other than EL6) my desktop automatically extends over to the USB 
monitor.  The KVM has a mode where you can switch keyboard and display, 
but leave all of the USB devices attached to the previous machine.  So I 
move interesting things to the small monitor, then switch only 
keyboard+display to another machine, and I can keep an eye on both machines.

So I do have the hardware (and can help test) -- I have not got it 
working through directly installing everything on my EL machine, but it 
did work back when I was using Ubuntu 10.04.

The Xorg drivers can be found here:
http://libdlo.freedesktop.org/wiki/xf86-driver-displaylink

I think the official udlfb driver in the kernel would fine for me.  When 
I was setting this up on Ubuntu, I found these in the repo, so was able 
to start doing the Xorg config right after installing the kernel module 
and the Xorg driver.  Here's an example of what the process sort of 
looks like on Ubuntu (though now the drivers are in the repo, so I 
didn't have to compile myself.)
http://mulchman.org/blog/?tag=displaylink

Anyway, its kind of neat to play with, if you get a chance, those little 
monitors are just really cool toys.  :)

Cheers,
Greg