help with mtd-test failures?

[Steve deRosier]

Hi all,

In doing my due dillegence on my system, I decided to run the
mtd-tests. I'm getting a few failures that I'd like your help in
understanding.

The one that worries me comes from mtd_oobtest:

    # modprobe mtd_oobtest dev=7
    mtd_oobtest: error: verify failed at 0x880000
    mtd_oobtest: error: verify failed at 0xe80000

The most worrysome thing about this is the fact that the result isn't
consistant. sometimes I get no failures, and sometimes they're at
different spots. I'll put the kmesg output later.

The other one is less concerning, but what do these failures from
mtd_nandecctest indicate?

    mtd_nandecctest: ok - no-bit-error-256
    mtd_nandecctest: ok - single-bit-error-in-data-correct-256
    mtd_nandecctest: ok - single-bit-error-in-ecc-correct-256
    uncorrectable error :
    mtd_nandecctest: ok - double-bit-error-in-data-detect-256
    uncorrectable error :
    mtd_nandecctest: ok - single-bit-error-in-data-and-ecc-detect-256
    uncorrectable error :
    mtd_nandecctest: ok - double-bit-error-in-ecc-detect-256
    mtd_nandecctest: ok - no-bit-error-512
    mtd_nandecctest: ok - single-bit-error-in-data-correct-512
    mtd_nandecctest: ok - single-bit-error-in-ecc-correct-512
    uncorrectable error :
    mtd_nandecctest: ok - double-bit-error-in-data-detect-512
    uncorrectable error :
    mtd_nandecctest: ok - single-bit-error-in-data-and-ecc-detect-512
    uncorrectable error :
    mtd_nandecctest: ok - double-bit-error-in-ecc-detect-512

I'm not very concerned because I believe from looking at the comments
that this doesn't actually utilize my hardware but is a software ECC
test and I'm using a hardware-based ECC.

My kernel version is 3.8.  I'm running on an Atmel SAM9G25 processor
with a Micron MT29F1G08ABBEAH4 SLC NAND.

All of the rest of the tests ran perfectly. And, are there any other
tests I should run to validate my hardware, kernel/driver setup, or
UBIFS?

The kmesg for the mtd_oobtest:

    =================================================
    mtd_oobtest: MTD device: 7
    mtd_oobtest: MTD device size 39845888, eraseblock size 131072,
page size 2048, count of eraseblocks 304, pages per eraseblock 64, OOB
size 64
    mtd_oobtest: scanning for bad eraseblocks
    mtd_oobtest: scanned 304 eraseblocks, 0 are bad
    mtd_oobtest: test 1 of 5
    mtd_oobtest: erasing whole device
    mtd_oobtest: erased 304 eraseblocks
    mtd_oobtest: writing OOBs of whole device
    mtd_oobtest: written up to eraseblock 0
    mtd_oobtest: written up to eraseblock 256
    mtd_oobtest: written 304 eraseblocks
    mtd_oobtest: verifying all eraseblocks
    mtd_oobtest: verified up to eraseblock 0
    mtd_oobtest: verified up to eraseblock 256
    mtd_oobtest: verified 304 eraseblocks
    mtd_oobtest: test 2 of 5
    mtd_oobtest: erasing whole device
    mtd_oobtest: erased 304 eraseblocks
    mtd_oobtest: writing OOBs of whole device
    mtd_oobtest: written up to eraseblock 0
    mtd_oobtest: written up to eraseblock 256
    mtd_oobtest: written 304 eraseblocks
    mtd_oobtest: verifying all eraseblocks
    mtd_oobtest: verified up to eraseblock 0
    mtd_oobtest: error: verify failed at 0x880000
    mtd_oobtest: error: verify failed at 0xe80000
    mtd_oobtest: verified up to eraseblock 256
    mtd_oobtest: verified 304 eraseblocks
    mtd_oobtest: test 3 of 5
    mtd_oobtest: erasing whole device
    mtd_oobtest: erased 304 eraseblocks
    mtd_oobtest: writing OOBs of whole device
    mtd_oobtest: written up to eraseblock 0
    mtd_oobtest: written up to eraseblock 256
    mtd_oobtest: written 304 eraseblocks
    mtd_oobtest: verifying all eraseblocks
    mtd_oobtest: verified up to eraseblock 0
    mtd_oobtest: verified up to eraseblock 256
    mtd_oobtest: verified 304 eraseblocks
    mtd_oobtest: test 4 of 5
    mtd_oobtest: erasing whole device
    mtd_oobtest: erased 304 eraseblocks
    mtd_oobtest: attempting to start write past end of OOB
    mtd_oobtest: an error is expected...
    mtd_oobtest: error occurred as expected
    mtd_oobtest: attempting to start read past end of OOB
    mtd_oobtest: an error is expected...
    mtd_oobtest: error occurred as expected
    mtd_oobtest: attempting to write past end of device
    mtd_oobtest: an error is expected...
    mtd_oobtest: error occurred as expected
    mtd_oobtest: attempting to read past end of device
    mtd_oobtest: an error is expected...
    mtd_oobtest: error occurred as expected
    mtd_oobtest: attempting to write past end of device
    mtd_oobtest: an error is expected...
    mtd_oobtest: error occurred as expected
    mtd_oobtest: attempting to read past end of device
    mtd_oobtest: an error is expected...
    mtd_oobtest: error occurred as expected
    mtd_oobtest: test 5 of 5
    mtd_oobtest: erasing whole device
    mtd_oobtest: erased 304 eraseblocks
    mtd_oobtest: writing OOBs of whole device
    mtd_oobtest: written up to eraseblock 0
    mtd_oobtest: written up to eraseblock 0
    mtd_oobtest: written up to eraseblock 256
    mtd_oobtest: written up to eraseblock 256
    mtd_oobtest: written 303 eraseblocks
    mtd_oobtest: verifying all eraseblocks
    mtd_oobtest: verified up to eraseblock 0
    mtd_oobtest: verified up to eraseblock 256
    mtd_oobtest: verified 303 eraseblocks
    mtd_oobtest: finished with 2 errors
    =================================================

Thanks,
- Steve