Re: [PATCH] blacklist NCQ on Seagate Barracuda ST380817AS

From: Jeff Garzik
Date: Sun Sep 30 2007 - 11:05:34 EST

Paolo Ornati wrote:
On Sun, 30 Sep 2007 15:29:08 +0100
Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:

Seagate Barracuda ST380817AS has troubles with NCQ. For example,
unpacking a tarball on an XFS filesystem gives this:

ata1.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x2 frozen
ata1.00: cmd 61/40:00:29:a3:98/00:00:00:00:00/40 tag 0 cdb 0x0 data 32768 out
res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
What makes you sure that is an NCQ problem ?

It goes away with:
echo 1 > /sys/block/sda/device/queue_depth

I have this problem only with XFS, and even with XFS it goes away
mounting with "nobarrier"...

This last is an interesting datapoint.

I wonder if libata has a generic problem with NCQ + FLUSH CACHE.

What happens if you enable the 'fua' module parameter? (libata.fua on kernel command line, if built in)


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