tree 5d5b71a27538e78453c7f4227aca8c94552e51ed
parent c97926dd8d7cc094830b253afc817cbf406c0de7
author Brian Norris <computersforpeace@gmail.com> 1314145052 -0700
committer Artem Bityutskiy <artem.bityutskiy@intel.com> 1315742537 +0300

mtd: do not assume oobsize is power of 2

Previous generations of MTDs all used OOB sizes that were powers of 2,
(e.g., 64, 128). However, newer generations of flash, especially NAND,
use irregular OOB sizes that are not powers of 2 (e.g., 218, 224, 448).
This means we cannot use masks like "mtd->oobsize - 1" to assume that we
will get a proper bitmask for OOB operations.

These masks are really only intended to hide the "page" portion of the
offset, leaving any OOB offset intact, so a masking with the writesize
(which *is* always a power of 2) is valid and makes more sense.

This has been tested for read/write of NAND devices (nanddump/nandwrite)
using nandsim and actual NAND flash.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>