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

[Arnaud Ebalard]

Robert Hancock <hancockrwd at gmail.com> writes:

>> 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.
>
> The commands that are failing are WRITE FPDMA QUEUED which is a
> regular NCQ write command. The ones that these commits add support for
> are FPDMA_SEND and FPDMA_RECV which are used for NCQ trim commands.
>
> It's possible that the feature detection for this is picking up
> support for FPDMA SEND/RECV on this drive when it shouldn't be. Can
> you post the output of "hdparm --Istdout /dev/sdX" for one of these
> drives (where X matches the drive in question)?

Will do that tonight and post the output.

a+