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Subject: Re: UBI: corrupted PEB detection for Numonyx P30
From: Artem Bityutskiy <dedekind1@gmail.com>
To: Holger Brunck <holger.brunck@keymile.com>
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Date: Tue, 25 Jan 2011 13:11:54 +0200
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Cc: "Walter, Axel" <Axel.Walter@keymile.com>, linux-mtd@lists.infradead.org,
	Detlev Zundel <dzu@denx.de>
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On Mon, 2011-01-24 at 14:12 +0100, Holger Brunck wrote:
>         err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
> -       if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR) {
> +       if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
> +           err1 == UBI_IO_FF || err1 == UBI_IO_FF_BITFLIPS) {
>                 struct ubi_ec_hdr ec_hdr;
> 
>                 err1 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
> -               if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR)
> +               if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
> +                   err1 == UBI_IO_FF || err1 == UBI_IO_FF_BITFLIPS) {
>                         /*
>                          * Both VID and EC headers are corrupted, so we can
>                          * safely erase this PEB and not afraid that it will be
> 
> Does anyone see a problem with this patch? If not I can post it as a git patch
> on the mailing list.

Hi, I agree with checking for UBI_IO_FF, but not for UBI_IO_FF_BITFLIPS,
because (a) NOR should not have them and (b) bit-flip means the the
header is correct, but there was a correctable bit-blip. But we want to
find the headers corrupted in this piece of code. 

I've prepared and pushed almost the same patch, made you the author:
http://git.infradead.org/ubi-2.6.git/commit/4782254b5f76c22726d270ea753816cefa088ae9

Please, take a look and check. If you do not like it, let me know or
just send the patch you like.

Thanks!

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)