queries regarding sub-page support

[Gupta, Pekon]

Hi,

I had few queries regarding sub-page support

(1)
With reference to following description, both Read & Write operations are allowed for sub-page accesses. 
http://www.linux-mtd.infradead.org/doc/ubi.html#L_subpage
However I could not find place-holder for '*write_subpage()' in  'struct nand_ecc_ctrl' .
Is there a particular reason for not including *(wrire_subpage)() ? Am I missing something ? 

(2)
As per ONFI spec 3.1, the 'partial-page' parameter present in 'NAND's parameter page structure' is not deprecated. 
>>111    Obsolete - Partial programming attributes 
Is there any other way to know, whether NAND device supports sub-page accesses ?

(3)
Is there any existing reference code to see the sub-page related changes ?


Thanks for help..
With regards, pekon