[MTD] [NAND] subpage read feature as a way to increase performance.

This patch enables NAND subpage read functionality.
If upper layer drivers are requesting to read non page aligned data NAND
subpage-read functionality reads the only whose ECC regions which include
requested data when original code reads whole page.
This significantly improves performance in many cases.

Here are some digits :

UBI volume mount time
No subpage reads: 5.75 seconds
Subpage read patch: 2.42 seconds

Open/stat time for files on JFFS2 volume:
No subpage read  0m 5.36s
Subpage read     0m 2.88s

Signed-off-by Alexey Korolev <[email protected]>
Acked-by: Artem Bityutskiy <[email protected]>
Acked-by: Jörn Engel <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>

0 files changed, 0 insertions, 0 deletions