Any objections/comments on axing out old ATA stack?

Bernd Walter ticso at
Sat Apr 20 12:42:31 UTC 2013

On Thu, Apr 04, 2013 at 12:15:32AM +0200, Matthias Andree wrote:
> I have just sent more information to the PR at
> The short summary (more info in the PR) is:
> - limiting tags to 31 does not help
> - disabling NCQ appears to help in initial testing, but warrants more
> testing
> - error happens during WRITE_FPDMA_QUEUED,
> - File system in question is SU+J UFS2 mounted on /usr, and I can for
> instance "rm -rf /usr/obj" or just log into GNOME and try to open a
> gnome-terminal to trigger stalls;
> - Linux uses 31 tags (for different reason) and has no drive quirks, but
> a controller quirk;
> for Jeremy's topic #6, regarding the ATI/AMD SB7x0 that I am using, it
> might be worthwhile investigating the AHCI_HFLAG_IGN_SERR_INTERNAL flag
> - it gets set by Linux on the SB700 that my computer is using, see
> ahci_error_intr() in libahci.h - I am not going to interpret that for
> lack of expertise, but it does affect error handling and appears to
> ignore a certain condition.
> Why only my Samsung HDD drive triggers this but not the WD drive, I do
> not know yet.

I have had data corruption with Samsung drive and CAM connected to
an onboard intel AHCI.
The system was known good running with an older FreeBSD version and was
brought back into service for another use case with a fresh installation.
Regulary on major filesystem write activity we got random FS corruptions
and panics.
My assumption was broen NCQ firmware on the drive, but have nothing to
proof this assumtion.
We switched to old ata driver and lived with this until we replaced the
whole machine.
Don't know if the machine still exists somewhere.

B.Walter <bernd at>
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.

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