Re: [PATCH v2 1/6] mtd: add writebufsize field to mtd_info struct

Artem Bityutskiy
2010-12-19T17:45:41Z

On Thu, 2010-12-16 at 23:42 +0100, Anatolij Gustschin wrote:
> This field will be used to indicate the write buffer size
> of the MTD device. UBI will set it's minimal I/O unit size
> (min_io_size) to the indicated write buffer size. By this
> change we intend to fix failed recovery of UBIFS partitions
> we currently observe on NOR flash when mounting the partition
> after unclean unmount.
>
> Currently the min_io_size is set to mtd->writesize (which is 1
> byte for NOR flash). But flash programming is often done from
> prepared write buffer containing multiple bytes and is performed
> in one programming operation which could be interrupted by a power
> cut or a system reset causing corrupted (partially written) areas
> in a flash sector. Knowing the size of potentially corrupted areas
> UBIFS scanning and recovery algorithms are able to perform
> successful recovery.
>
> In case of NOR flash minimal I/O size must be equal to the
> maximal size of the write buffer used by embedded flash
> programming algorithm. In case of NAND flash mtd->writebufsize
> should be equivalent to mtd->writesize.
>
> The subsequent patches will add mtd->writebufsize initialization
> where needed.
>
> Signed-off-by: Anatolij Gustschin <agust@denx.de>

I've tweaked your commentary a bit and pushed to l2-mtd-2.6.git, please,
check.

--
Best Regards,
Artem Bityutskiy (Битюцкий Артём)