Re: [PATCH 0/9] drivers:mtd:UBI: add bakvol module for MLC NAND paired page issue
From: Boris Brezillon
Date: Wed Sep 30 2015 - 03:34:58 EST
On Wed, 30 Sep 2015 05:31:43 +0000
Bean Huo éææ (beanhuo) <beanhuo@xxxxxxxxxx> wrote:
> > Am 28.09.2015 um 09:02 schrieb Bean Huo éææ (beanhuo):
> > > 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.
> > >
> > > 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.
> > As stated before, using OOB in UBI is not going to happen unless proven that
> > there is absolutely no other way to solve the paired pages problem.
> > Nacked-by: Richard Weinberger <richard@xxxxxx>
> > Sorry,
> > //Richard
> Hi, Richard
> Thanks for your concern. I am a new patch submitter.
> Can you tell me Nacked-by means?
> By the way, Do you review my patches series ? I don't backup duplicated data in OOB .
That's not what Richard said, he just pointed that you were using the
OOB area, and you're actually using it to store the information about
which page you're backuping.
> Can you specify which sector codes ? so that I can explain it in detail.
And as answered by Richard, check_original_data() and
mtd_write_dual_plane_oob() are filling the OOB buf with the original
page offset, so you're definitely using the OOB area to store metadata.
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/