Re: hsm violation

From: Robert Hancock
Date: Sun Jun 24 2007 - 15:42:19 EST


Andrew Morton wrote:
On Sun, 24 Jun 2007 14:32:22 +0200 Enrico Sardi <enricoss@xxxxxxxxxx> wrote:
[ 61.176000] ata1.00: exception Emask 0x2 SAct 0x2 SErr 0x0 action 0x2 frozen
[ 61.176000] ata1.00: (spurious completions during NCQ issue=0x0 SAct=0x2 FIS=005040a1:00000004)

..


It's not obvious (to me) whether this is a driver bug, a hardware bug,
expected-normal-behaviour or what - those diagnostics (which we get to
see distressingly frequently) are pretty obscure.

The spurious completions during NCQ error is indicating that the drive has indicated it's completed NCQ command tags which weren't outstanding. It's normally a result of a bad NCQ implementation on the drive. Technically we can live with it, but it's rather dangerous (if it indicates completions for non-outstanding commands, how do we know it doesn't indicate completions for actually outstanding commands that aren't actually completed yet..)

--
Robert Hancock Saskatoon, SK, Canada
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