Hello,
on my AT91SAM9263 based board RT patched kernel works great! Thanks to 
all involved. But when ethernet is in use - latency, measured by 
cyclictest, reach 7000000 and beyond.
The ethernet driver for this processor is macb.c. (in 3.2 it is in 
drivers/net/ethernet/cadence, in 3.0 it is in drivers/net/).
I'm ready to find out how to RT-patch it and of course share the 
resulted patch, but I need some starting point for patching drivers 
besides general RT-stuff.  I've noticed that some network drivers 
patched in one way and others a in another. Maybe some discussion 
existed which I didn't found. So any help would be greatly appreciated.
Thanks in advance,
Mikhail