Hmm, unfortunately, it's usage is not clearly documented in mtd- 
physmap.txt,

It's pretty clear I think.  Patches for making it better are welcome  
of course.

so I never thought of this parameter.  And IMHO the problem goes  
further - basically *any* chip which is attached to the LPB can be  
affected by this problem, so it might be better to have a more  
general approach like a "chip select property".

You cannot treat devices on the LPB as random access, that's all.   
Drivers
that assume they can, cannot be used for devices on the LPB.


Segher