Re: NAND OOB Questions...

[Thomas Gleixner <tglx@linutronix.de>]

On Tue, 2006-06-06 at 07:12 -0700, Steve Finney wrote:
> >Yeah. I did not think about that abstruse scenario :) What the hell is
> >this for ?
> 
> Well, I didn't go looking for bugs :-). The hardware is the board I'm working on,
> and what I wanted to do was force single bit errors to verify that the read correction
> code worked. My way of doing that was to let the kernel write the correct ECC, 
> and then read it back, corrupt a single data bit, and write the data +OOB back with unchanged
> OOB. It didn't work :-(.

Ok. Makes sense.

> As long as I'm here...is there any clever way of clearing a bad block marker? I realize
> you do _not_ want to do this in the real world, but I created a few fake bad blocks for
> testing purposes and there seems to be no way to get rid of them; neither Linux nor U-Boot
> will let you call erase on a bad block. You can recompile U-Boot to allow it to do so, but
> I'm wondering if there's any other way.

Yes, switch the bad block stuff off in the kernel. :) You can do this
also from your module by overriding the block_bad function.

	tglx