How to write an X driver..?

[Florian Echtler]

Hello everyone,

as posted previously, I'm on the way to writing a driver for DisplayLink
devices. Unfortunately, I'm a bit at a loss on where to start. I've
noticed that it seems pretty easy to write a framebuffer driver and run
an X server with fbdev on top of that. 

However, as the DisplayLink devices are connected through the USB
bottleneck which makes even plain PCI look blazingly fast by
comparision, I'm not sure whether that approach would throw away a lot
of optimization potential, like storing pixmaps in unused areas of the
video memory.

Can somebody please give me some hints? Where should that kind of
optimization happen, in the driver?

Yours, Florian
-- 
0666 - Filemode of the Beast