Numonyx NOR and chip->mutex bug?

Michael Cashwell mboards at
Fri Feb 11 10:05:54 EST 2011

On Feb 10, 2011, at 12:54 PM, Anders Grafström wrote:

> On 2011-02-10 17:43, Michael Cashwell wrote:
>> On Feb 10, 2011, at 10:59 AM, Michael Cashwell wrote:
>> Troublesome 65nm parts:
>> run 1:
>> NOR Flash: block erase suspended and resumed 29 times.
>> buffered write fails.
> Buffered write fails with SR[4] set?

The error messages variously report block locked and Vpp errors but they are not legitimate. I changed them to actually print the status word and it's often 0xffff or other values with set bits in the upper byte. That tells me the chip is not properly in status-read mode at that point.

So I think the answer to your question is no, not reliably with SR[4] set because it's reading array data instead of status.

> Have you configured with CONFIG_MTD_UBI_DEBUG_PARANOID so that UBI does the all 0xff check after erase?

I've used some of the debugging modes at the top of cfi_cmdset_0001.c but I had not used the config option. I will do that and report back.

> I'm wondering if the blocks being written to are in a properly erased state.

Yes, it's a possibility. However, I've never seen an erase report any error.

More next week.


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