mtd oob test is failing consistently at same places in NAND flash

[Ricard Wanderlof]

On Tue, 8 May 2012, Philip, Avinash wrote:

> I add debugs and found bit flips from 1 to 0. The location of bit flips might vary on
> boards. But on the same board it is consistent.
>
>>> To verify further we had tried writing zeros to OOB area and read it back.
>>> This test is passing and confirms that all OOB bits (that are
>>> programmable) are not bad.
>>
>> It does not confirm anything, bits can fail by remaining stuck at 0.
>>
>
> As bit flip is from 1 to 0, you are right. But same experiment with 0x55,
> test is passing.

Are you sure it's not the bits that happen to be 0 in 0x55 that are the 
ones suspected of flipping?

/Ricard
-- 
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
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