On 11/11/06, Charles Manning <manningc2@actrix.gen.nz> wrote:
> On Saturday 11 November 2006 03:53, Vitaly Wool wrote:
> > On 11/10/06, Aubrey <aubreylee@gmail.com> wrote:
> > > Hi Vitaly,
> > >
> > > On 11/10/06, Vitaly Wool <vitalywool@gmail.com> wrote:
> > > > this is a known issue on 2.6.18 kernels. It is caused by the MTD layer
> > > > rework and corresponding yaffs-mtd layer modifications. Namely, an
> > > > additional translation had to be implemented for OOB area for 512b
> > > > page chips.
> > >
> > > Oh, thanks very much to point it out.
> > > So, What should I do to fix this issue? Upgrade mtd directory in the
> > > kernel to the newest version? ( I think I have already had the newest
> > > yaffs), thanks again to give me any suggestions.
> >
> > You'll have to do some code hacking to speed things up. I.e. you'll
> > need to set up your OOB layout according to SmartMedia spec and then
> > you'll be able to remove the translation shim in yaffs code.
>
> It is important to understand this:
>
> The mtd NAND driver is generic code that is parameterised by configuration
> tables to make it flexible. This gives an (almost/often) out of the box
> experience, and IMHO, is pretty slick code, but there's a cost associated
> with the flexibility.
>
> A custom driver can be a lot faster, but then it won't be generic any more.
>
> Most people who want fast NAND speed end up writing their own custom drivers
> to maximise ransfer with their hardware.
>

Sorry, I'm a little confused. So Should I do some specific change for
my NAND chip in the mtd NAND driver or besides it, I also should do
some code hacking on the yaffs?

I'm afraid I need a more time to read the source code to understand
why. My driver works fine on the former yaffs, and in 2.6.18, my
driver works fine as well on JFFS2, why do I need to write some not
generic pieces of code to speed up mount time on the current YAFFS2?

-Aubrey