[LEDE-DEV] Need fix / advice / idea

[Denis Periša]

>> Just curious, this bad sectors appeared during regular device
>> operation or just after sysupgrade?


Sysupgrade. I had to get to roof and replace device as I could no
longer get firmware on it. Btw. I wrote that it would be nice to first
check nand than write if possible. sysupgrade told me that firmware
was flashed successfully but on reboot no kernel was found.

>> I am asking because it could be "false positive" bad sectors. Couple
>> of weeks ago I flash one rb411 with wrong image. I used image for
>> flash chips with 512-bytes pages, while the board was equipped with
>> flash chip with 2048-bytes pages. And after reboot kernel printed a
>> lot of "bad sector" messages. Actually sectors was fine, but using of
>> the wrong firmware image lead to corruption of OOB data of several
>> pages.
>>
>> I solved this issue by flashing back the vendor's firmware with help
>> of netinstall, this action had recover flash OOB. Then I flash the
>> device again, but now with the correct LEDE image and it works! Looks
>> like that the similar results could be reached with _nandwrite_
>> utility, but I did not try it.

You might be on to something there, I had same device and it was brand
new out of box.. Flashed firmware once, flashed twice, lot more bad
sectors, next time whole nand was bad. That time I experimented with
yaffs1 and yaffs2, had lot of issues there. Returned it as RMA same
day, got another device. I actually tried to find how I could from
linux re-detect or re-check how to put it, those bad sectors but
didn't find any info. This yours is very helpful info, I'll try that
and return here, but question stays, maybe in future some NANDs will
begin to fail. This could be helpful in future.

Thank you!