[BUG,REGRESSION] SATA regression on 12.0-rc4 kernel

[Arnaud Ebalard]

Hi Robert,

Robert Hancock <hancockrwd at gmail.com> writes:

> On 10/07/2013 01:12 PM, Arnaud Ebalard wrote:
>> Hi guys,
>>
>> yesterday, I reported on arm kernel mailing list what looked like a sata
>> regression on my platform (Marvell Armada 370-based NETGEAR ReadyNAS
>> 102). I initially thought this was an ARM-related issue. My initial
>> email, provided below, contains various details on the platform and the
>> error encountered.
>>
>> Today, before starting a painful git bisect, I decided to git log
>> sata_mv.c code and then more generally drivers/ata to quickly end up on
>> commit ed36911c747c (libata: Add support for SEND/RECEIVE FPDMA QUEUED)
>> against which I got suspicious after looking again at the errors I had:
>>
>> [  417.288155] ata1.00: exception Emask 0x0 SAct 0x1fff6001 SErr 0x0 action 0x6 frozen
>> [  417.295838] ata1.00: failed command: WRITE FPDMA QUEUED
>> [  417.301097] ata1.00: cmd 61/48:00:80:ad:0b/00:00:0c:00:00/40 tag 0 ncq 36864 out
>> [  417.315896] ata1.00: status: { DRDY }
>> [  417.319570] ata1.00: failed command: WRITE FPDMA QUEUED
>> [  417.324814] ata1.00: cmd 61/08:68:70:a1:87/00:00:0d:00:00/40 tag 13 ncq 4096 out
>> [  417.339619] ata1.00: status: { DRDY }
>> [  417.343288] ata1.00: failed command: WRITE FPDMA QUEUED
>> [  417.348536] ata1.00: cmd 61/08:70:28:a2:87/00:00:0d:00:00/40 tag 14 ncq 4096 out
>> [  417.363341] ata1.00: status: { DRDY }
>> [  417.367010] ata1.00: failed command: WRITE FPDMA QUEUED
>> [  417.372257] ata1.00: cmd 61/08:80:80:a3:87/00:00:0d:00:00/40 tag 16 ncq 4096 out
>> [  417.387061] ata1.00: status: { DRDY }
>> [  417.390733] ata1.00: failed command: WRITE FPDMA QUEUED
>> [  417.395977] ata1.00: cmd 61/08:88:58:a1:c7/00:00:0d:00:00/40 tag 17 ncq 4096 out
>> [  417.410782] ata1.00: status: { DRDY }
>>
>> Reverting both 87fb6c31b9 (libata: Add support for queued DSM TRIM) and
>> ed36911c74 (libata: Add support for SEND/RECEIVE FPDMA QUEUED) makes the
>> problem disappear. Note: reverting 87fb6c31b9 is not enough and I cannot
>> compile the kernel with only the latter reverted.
>>
>> If you need more info on the platform or want me to test something some
>> fix, do not hesitate.
>
> I assume that it consistently fails on a non-working kernel and
> consistently works with those patches reverted? Given that both of
> those patches seem to only be touching SSDs with NCQ trim support, it
> seems odd they would be breaking a normal hard drive, but maybe there
> is some unexpected side effect..

With two different disks (same model though, i.e. 250GB 3.5" WD blue), it
consistently works on a 3.11.4 and consistently fails on 3.12-rc3 and
3.12-rc4 (not tested others 3.12-rc). The problem is easy to reproduce,
i.e. I just need to perform some disk operations. With the two commits
reverted from 3.12-rc4, I can consistently do a "find / -exec sha256sum
'{}' \;" w/o anything happening.

What I do not understand is why the log report failed FPDMA commands if
the feature is supposed to be SSD-related (looking only at commit
messages: 87fb6c31b9 seems SSD-related, ed36911c74 does not). Is it
possible that the feature detection is what is causing the issue? Or
that the hardware report support w/o having? I can test with a different
disk if you think it would help.

Cheers,

a+