3 extra driver need to develop for GTA03

[Alan Cox]

> The Linux serial driver is an abomination in itself (the only saving grace is 
> that it's largely compatible back to the days of the ASR33 teletype machine). 

We do 2Mbits/sec quite happily.

> IMO, if performance is the goal, we need to consider a custom high-speed serial 
> driver for the UART connected to the GSM, one that gets rid of the overhead of 
> the entire tty layer in the kernel.

What overhead. If you are driving the tty layer properly on a modern
kernel you should have almost no overhead from the tty layer. If not
collect profile traces from 2.6.24 or later, gprof them, produce the
graphs and file a bug.

Alan