OneNAND: Update OOB free table

Kyungmin Park kyungmin.park at
Thu Dec 21 20:52:01 EST 2006


> > On Mon, 2006-12-18 at 04:24 +0000, Kyungmin Park wrote:
> > > How about the this patch?
> > > It skips the ecc position which is defined in ecc layout in mtd drivers.
> > 
> > Here is my understanding of the problem.
> > 
> > Nowadays MTD supports nicer interface to work with OOB. This is the
> > MTD_OOB_AUTO command. Currently JFFS2 uses old MTD_OOB_PLACE command.
> > 
> > The idea behind the MTD_OOB_AUTO command is that user provides buffer
> > with his data, and MTD takes care about how to put it to the OOB area,
> > MTD knows which OOB bytes may be used. Similar for reading OOB - MTD
> > automatically reads data bytes, skips ECC, and returns the data.
> > 
> > So what we should do is to teach JFFS2 using MTD_OOB_AUTO instead of
> I may try to do this, but only in 2007. Vitaly said he may also try to
> do this later.
> Also, dwmw2 is concerned about compatibility, so we should explore this
> too.

Okay, I understand the MTD_OOB_AUTO concept. but now JFFS2 only use the MTD_OOB_PLACE. 
so JFFS2 skip the ecc position for backward compatibility.

> Kyungmin, may you make sure OneNAND is OK WRT MTD_OOB_AUTO?

Now OneNAND don't support MTD_OOB_AUTO, but if the jffs2 supports the this one. I will support it.
I think it's more reasonable to handle oob in driver level instead of filesystem.

> Also Kyungmin, in you driver I see touch_softlockup_watchdog() calls. I
> believe they should not be there. You must be hid a problem with this
> instead of fixing it. Please, look at that stuff.

Actually, I'm not sure where's the right place. But if we don't touch the watchdong.
it will soft lockup when mounting the JFFS2 with big partition. (I just borrowed it from nand.)

> Kyungmin, do you have your own OneNAND git tree? If yes, what's the URL?
> How about putting it on, just like we have our UBI git
> there?

No, I used it in but I just used for commit.;a=summary

Today, I will commit the onenand patches for test.

Thank you,
Kyungmin Park

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