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

Robert Hancock [off-list ref] writes:

quoted

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+