Messages in this thread | | | Date | Mon, 28 Sep 2015 09:41:34 +0200 | From | Boris Brezillon <> | Subject | Re: [PATCH 0/9] drivers:mtd:UBI: add bakvol module for MLC NAND paired page issue |
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Hi Bean,
Next time you send a patch series, could send all the patches in reply to the cover letter?
On Mon, 28 Sep 2015 07:02:35 +0000 Bean Huo 霍斌斌 (beanhuo) <beanhuo@micron.com> wrote:
> Hello, > > This series aims at adding a bakvol module for MLC NAND paired page > Power loss protection. > MLC NAND paired page power loss is a known issue so far, MLC NAND pages are > coupled in a sense that if you cut power while writing to a page, you corrupt not only > this page, but also one of the previous pages which is paired with the current one. > Currently, there is no a perfect solution for this. > This paired page solution is based on NAND multiple plane program feature. For this > Patch, only used dual plane page program, means two different plane pages can > Be programmed together at the same time. > Dual plane page program only implements in backup operation. Only lower page data > Be duplicated and back up into a internal log volume by dual plane program method.
Hm, I'm not very fond of the idea, especially because of the complexity caused by dual plane program operations (you can't take a random block to write your backup on it, which means WL is complexified too), and the fact that you're duplicating data (thus introducing a performance penalty and storage overhead).
> > This patch has been testing on Micron 70s/80s/90s MLC NAND. > Of course there are some places needed to be improved and simplified. > > Any suggestion and comments welcomed.
Sure, I'll try to review it soon.
Thanks for submitting those patches.
Best Regards,
Boris
-- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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