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From: Calvin Walton <>
To: Hugo Mills <>
Subject: Re: Spurious completions during NCQ
Date: Fri, 15 Feb 2008 10:00:00 -0500	[thread overview]
Message-ID: <1203087600.25150.5.camel@zem> (raw)
In-Reply-To: <>

On Fri, 2008-02-15 at 13:46 +0000, Hugo Mills wrote:
> I'm getting these on my Dell Latitude D830:
> Feb 15 13:06:00 willow kernel: ata1.00: exception Emask 0x2 SAct 0x4 SErr 0x0 action 0x2 frozen
> Feb 15 13:06:00 willow kernel: ata1.00: spurious completions during NCQ issue=0x0 SAct=0x4 FIS=004040a1:00000002

>    In some cases, there are several cmd/res lines listed. It's
> happening about once an hour or so (not correlated with any other
> event that I can see). It doesn't seem to be affecting operation of
> the machine, but it's making me nervous.
>    Can anyone set my mind at rest? (Or suggest a fix?)

You didn't mention which SATA chipset your laptop has, but some quick
googling says that it's AHCI. Until 2.6.24, the AHCI driver has a
problem where it'll report superious NCQ completions due to a bug in the
driver logic.

> uname -a reports:
> Linux willow #1 SMP Sun Nov 4 14:51:20 GMT 2007 x86_64 GNU/Linux

The fix is simple, upgrade your kernel to 2.6.24 :)

>    It's a kernel with the patch for tickless operation on
> amd64.

Handily, the 2.6.24 kernel includes amd64 tickless support

Calvin Walton <>

  reply	other threads:[~2008-02-15 15:00 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-15 13:46 Spurious completions during NCQ Hugo Mills
2008-02-15 15:00 ` Calvin Walton [this message]
2008-02-15 15:04   ` Hugo Mills
2008-02-15 15:37     ` Michael Tokarev
2008-02-16 14:08 ` Mark Lord
2008-03-06  5:56   ` Tejun Heo
2008-03-06  6:05     ` Tejun Heo
  -- strict thread matches above, loose matches on Subject: below --
2007-10-13 13:12 Marco Lamberto
2007-09-07 17:57 Sumanth J.V

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