[RFC][patch] NAND partial page read functionality

[Artem Bityutskiy]

On Thu, 2008-04-24 at 17:45 +1000, Hamish Moffatt wrote:
> The rest of the discussion was about improved use of sub-page writes.
> I'm sure that would be useful but it's not strictly relevant to the
> partial read patch.
Yup.

> Artem, were you able to try the patch on the OLPC with hardware ECC, as
> you hinted in the original discussion?

Right, I completely forgot to do this. I've just verified - OLPC works
just fine with this patch. It also does not affect our OneNAND setup.

> Also I reverted your recent patch to combine the EC + VID header reads
> in the UBI scan for this test. I think with partial reads it may make 
> things slower, because it will force 2K to be read (or 576 bytes if the 
> ALIGN() is removed, still more than 64 + 64). Because min_io_size = 2K
> is not really accurate I guess.

I deliberately did that. I though making one call instead of 2 is
better, because MTD anyway reads whole page. And my other motivation was
that flashes like OneNAND which may read 2 consecutive pages faster
(kind of "burst" read). Although for OneNAND this trick does not really
work. Anyway, lets forget about that patch.

I think if Alexey is not any more interested in working on his patch,
you could do this, if you are interested. I am going to be away till the
5 of May, so I won't be able to help.

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)