Subject: pxa3xx_nand times out in 4.14 with JFFS2

From: [email-masked] (Willy Tarreau)
Date: Sun, 17 Dec 2017 17:23:42 +0100

On Sun, Dec 17, 2017 at 12:53:36PM -0300, Ezequiel Garcia wrote:
> If not too much to ask, this is the test that I believe is needed.
> You seem to have a setup ready, hence why I'm asking you, if
> possible, to give it a shot.
> 
> (1) Scrub the BBT from the NAND. Or scrub the whole NAND.
> You cannot do this from the kernel, it needs to be done from the bootloader.
> 
> (2) Mark a couple blocks as bad using the OOB -- AFAICR, there
> was a command to do this in the bootloader.
> 
> (3) Boot, let Linux create the BBT and see if it catches the bad blocks.

Are the current boot loaders safe regarding the scrub operation ? I'm
asking because that's how I bricked my mirabox a few years ago when
trying to mark a bad block from u-boot :-/  If someone has a good
knowledge of these commands to limit the risk and helps me only playing
with a small part at the end of the flash (or in the unused area) I'd
prefer it :-)

> This would guarantee that devices with factory bad blocks,
> (and no BBT), would be OK with this patch.

I see. I'm fine with trying provided I have reasonably good assurance
that I won't have to go through the kwboot pain again :-/

Cheers,
Willy