[PATCH v2] UBI: only read necessary size when reading the VID header

[Artem Bityutskiy]

On Tue, 2016-06-28 at 10:49 -0700, Brian Norris wrote:
> In reading Artem's first objection, I was noticing the same thing and
> came to a similar conclusion. I guess we can't really get by with UBI
> just guessing at the ideal read size. Right now, it gets it too large
> most of the time, since often, NAND controllers can support sub-page
> reads, but not sub-page writes (or even if the controller can, the
> flash
> can't -- like all MLC or even many modern SLC), so a single number
> (writesize >> subpage_sf) is not sufficient.

Yes, this is a good opportunity for speed optimizations indeed.