[Libdlo] linux kernel fraebuffer driver update

[Greg KH]

On Thu, May 21, 2009 at 06:49:29PM +0200, Roberto De Ioris wrote:
> Hi all, the fbcon driver for displaylink is quite ready.
> 
> I am working on y wrap acceleration but i think tomorrow i will post it.
> 
> In the driver you will find a non-standard ioctl that takes an area as
> parameter. Sending this ioctl force the displaylink framebuffer to
> commit the gfx area to the device. In this way writing a first
> (prototype) xorg driver would be simple. (a standard framebuffer driver
> + a call on the ioctl on every update would be sufficient)

Very cool, I'm interested in seeing this code, and providing any help
that I can.

> I am not sure that putting compression in the kernel side is a good
> thing, so i am working even on a total userspace (libusb based) xorg
> driver.

Hm, that might not work out well with the new way xorg is working these
days.  Compression in the kernel shouldn't be a problem (we should
already have the needed libraries for this, if not, let me know.)

For a stand-alone xorg server, a userspace driver would work well.  But
if we need to move windows from the internal gpu to the display link
device, that gets messy.  I've been talking with some of the xorg
developers on a way to "bolt on" the DL device as just another "monitor"
and have the internal GPU do the heavy lifting and rendering, and the DL
connection just sends the resultant data.  That will work out much
better with the new xorg driver model as shown in the intel driver.

Down side is that we have to modify every GPU driver, which could get
messy, and impossible in places (like nvidia).

But a working xorg driver to start with would be invaluable, and very
useful for a lot of other situations, so don't let me disuade you from
doing it.

thanks,

greg k-h