[Yaffs] Yaffs with 2k Pages OR Yaffs2

Charles Manning Charles.Manning@trimble.co.nz
Mon, 20 Dec 2004 09:38:47 +1300


Thomas

The YAFFS list isn't really the place to argue the kernel version issue.
I have no doubt that the newer kernel is "better", but there are many
factors that come into making the decision as to what version you are
going to ship. If you already have a stable shipping product then
changing kernel can be a big issue. That is my major reason for keeping
more mature kernel support in YAFFS.

Doing some relatively minor hacks to an old mtd is an option that Rajiv
has to overcome his current issues and get going with YAFFS2. There are
many factors which drive the choices he has to make (hack old mtd vs
revamp kernel). I don't wish to force any decision on him as I know I
don't have the information I need to make that decision.

BTW: At home my desktop runs 2.4.18 most of the time (and 2.4.27 some of
the time). The reason I don't run 2.4.27 all the time is because some
network etc drivers I have would need rebuilding -- something I have not
bothered to do. The reason I don't use 2.6.x at present is similar. I'm
no Luddite, but the amount of gain vs pain in not enough to motivate me
to change.

-- Charles




> -----Original Message-----
> From: Thomas Gleixner [mailto:tglx@linutronix.de]=20
> Sent: Monday, 20 December 2004 9:10 a.m.
> To: Charles Manning
> Cc: Rajiv Dhingra; YAFFS
> Subject: RE: [Yaffs] Yaffs with 2k Pages OR Yaffs2
>=20
>=20
> On Mon, 2004-12-20 at 08:59 +1300, Charles Manning wrote:
> > Rajiv
> >=20
> > I've thought about this a bit...
> > While Thomas it technically correct that YAFFS2 needs more=20
> recent mtd=20
> > (which no longer supports older kernels), I think it rather=20
> simple to=20
> > hack the mtd you have to support YAFFS2.
> >=20
> > Basically, all you'd need to do is:
> > 1) Modify the nand write/read functions to work with 2k=20
> pages (change=20
> > the size of the for loop), and a few other minor changes to=20
> handle ECC=20
> > etc.
> > 2) Add a couple more required fields to the mtd_info structure.
> > 3) Add two new functions block_markbad() and block_isbad() for bad=20
> > block handling.
>=20
> So you finally backport the whole mtd driver. :)
>=20
> > Whether it is the right time for you to switch to a newer kernel or=20
> > not is your choice and should not be forced by mtd changes.
>=20
> What real good reason is there not to upgrade the kernel ?=20
> Backporting major changes is worse than upgrading. Especially=20
> if the base you use is well known to be buggy and obsolete.
>=20
> tglx
>=20
>=20
>=20
>=20