[LEDE-DEV] flash issue

[Conor O'Gorman]

0x1985 is a jffs2 magic marker value. Look up the jffs2 code. So it's 
not a bogus value that might come from a 'bad' flash. More likely is 
that you have some issue with flash partition sizes, possibly as you 
have a non-standard flash size anyway.
Look carefully at the boot log for the flash partitioning.

Conor


On 20/07/16 19:59, e9hack wrote:
> Hi,
>
> I've some trouble to update my router. It is a TP-Link WDR3600 with an increased flash
> (16MB instead of 8MB). If I update the router, I get very often a message after the first
> reboot like this:
>
> [   62.840041] jffs2: Newly-erased block contained word 0x19852003 at offset 0x00000000
>
> If an image produces this error, it occurs at every update with this image. It is for
> different images the same word and offset. If it occurs, the router works perfectly. WLAN
> is up and I don't see any issue. After the next reboot, the router does overwrite most (or
> all) files, which are usually generated if sysupgrade is used with option -n. All other
> files will be not overwritten. For example, /etc/shadow isn't overwritten. I've some old
> configuration files and backups in /etc/config. They will be not overwritten. The old
> password is still active and dropbear is running. During my tests, I did restore the
> configuration by an previously saved backup. This means, the overlay fs contains all the
> time the same, if I update the router with an image.
>
> The message comes from the second entry of this message in linux-4.4.15/fs/jffs2/read.c. I
> did modify the code in a way, that at maximum 16 wrong locations will be print. I see 8:
>
> [   61.770067] jffs2: Newly-erased block contained word 0x19852003 at offset 0x00000000
> [   61.778274] jffs2: Newly-erased block contained word 0xc at offset 0x00000004
> [   61.785816] jffs2: Newly-erased block contained word 0xf060dc98 at offset 0x00000008
> [   61.793985] jffs2: Newly-erased block contained word 0x1985e001 at offset 0x0000000c
> [   61.802113] jffs2: Newly-erased block contained word 0x36 at offset 0x00000010
> [   61.809727] jffs2: Newly-erased block contained word 0x5d4448fe at offset 0x00000014
> [   61.817868] jffs2: Newly-erased block contained word 0x1 at offset 0x00000018
> [   61.825368] jffs2: Newly-erased block contained word 0x0 at offset 0x0000001c
>
> During implementing this, I generate several images with some small differences. This 8
> values are all the time the same. From my experience with i²c eeproms with too much write
> cycles, errors starts with single bits in one byte of one page. Eeproms are different than
> spi flash’s, but currently I don't assume, that the flash is damaged. I will verify this
> by replacing the flash.
>
> I'm using a second router. It is a TP-LINK C7. The cpu is the same family and
> configuration to build the image is more or less the same. It has already a 16MB flash by
> default. I don't see such errors.
>
> I'm not sure if this error did occur with OpenWrt in the past. I did flash some old
> images, but I didn't see this error with OpenWrt images.
>
> Regards,
> Hartmut
>
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