I've finally straightened out all the configuration issues and now have yaffs2 in the kernel tree so that it will configure and build properly.  meanwhile, i've also gotten the p2 NAND driver stabilized.  I'm seeing some interesting bugs in yaffs2 on a Samsung NAND part, but it is stable enough to run some benchmarks.
 
Is anyone interested in patches that allow yaffs2 to compile properly in-tree in 2.6.11.12?
 
marty