[U-Boot] [PATCH resend V2 1/3] mtd: nand: mxs support oobsize bigger than 512

Scott Wood
2015-08-01T18:54:48Z

On Sat, 2015-08-01 at 20:38 +0200, Marek Vasut wrote:
> On Saturday, August 01, 2015 at 08:32:07 PM, Scott Wood wrote:
> > On Sat, 2015-08-01 at 17:18 +0200, Marek Vasut wrote:
> > > On Saturday, August 01, 2015 at 07:56:39 AM, Peng Fan wrote:
> > > > On Fri, Jul 31, 2015 at 09:36:45PM -0500, Scott Wood wrote:
> > > > > On Sat, 2015-08-01 at 09:15 +0800, Peng Fan wrote:
> > > > > > On Fri, Jul 31, 2015 at 12:07:50PM -0500, Scott Wood wrote:
> > > > > > > On Tue, 2015-07-21 at 16:15 +0800, Peng Fan wrote:
> > > > > > > > If ecc chunk data size is 512 and oobsize is bigger than 512,
> > > > > > > > there
> > > > > > > > is a chance that block_mark_bit_offset conflicts with bch ecc
> > > > > > > > area.
> > > > > > > >
> > > > > > > > The following graph is modified from kernel gpmi-nand.c driver
> > > > > > > > with
> > > > > > > > each data block 512 bytes. We can see that Block Mark
> > > > > > > > conflicts
> > > > > > > > with
> > > > > > > > ecc area from bch view. We can enlarge the ecc chunk size to
> > > > > > > > avoid this problem to those oobsize which is larger than 512.
> > > > > > >
> > > > > > > Enlarge it by how much? What does the layout look like in that
> > > > > > > case?
> > > > > >
> > > > > > Enlarge it to 1024 bytes.
> > > > >
> > > > > Then say so in the changelog.
> > > >
> > > > You mean I need to add this in commit msg and send out a new patch
> > > > version?
> > > > Or you pick this one?
> > >
> > > This discussion is becoming ridiculous, can we please get this bugfix
> > > applied ?
> > > If you don't like some minor details in the commit message, can you
> > > please fix
> > > them while applying ?
> >
> > Yes, I can edit the changelog while applying, but that doesn't mean I'm
> > not
> > going to complain about a difficult-to-understand changelog, and I still
> > would like to understand what is actually going on here. Don't assume I'm
> > familiar with this hardware or its unusual page layout. You can help by
> > explaining things, or you can not help by throwing a fit...
>
> I can point you to MX28 datasheet [1] chapter 16.2.2 and onward if you want
> to educate yourself, it's all explained there, concisely and clearly.
>
> [1] http://free-electrons.com/~maxime/pub/datasheet/MCIMX28RM.pdf

Thanks. That preempted a question I was just about to ask Peng, because it
wasn't clear that the meta area was covered by ECC.

-Scott