From: linas@austin.ibm.com (Linas Vepstas)
To: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH] pSeries: EEH improperly enabled for some Power4 systems
Date: Fri, 26 Jan 2007 16:53:11 -0600 [thread overview]
Message-ID: <20070126225311.GD11220@austin.ibm.com> (raw)
In-Reply-To: <17850.33057.686491.685870@cargo.ozlabs.ibm.com>
On Sat, Jan 27, 2007 at 09:30:57AM +1100, Paul Mackerras wrote:
> Linas Vepstas writes:
>
> > It appears that EEH is improperly enabled for some Power4 systems.
> > On these systems, the ibm,set-eeh-option returns a value of success
> > even when EEH is not supported on the given node. Thus, an explicit
> > check for support is required.
>
> What happens on the power4 systems when EEH is improperly enabled?
>
> What systems has the patch been tested on?
Sorry, I should have said more from the get-go.
During boot, on power4, without this patch, one sees messages
similar to:
EEH: event on unsupported device, rc=0 dn=/pci@400000000110/IBM,sp@1
EEH: event on unsupported device, rc=0 dn=/pci@400000000110/pci@2
EEH: event on unsupported device, rc=0 dn=/pci@400000000110/pci@2,2
etc.
The patch makes these go away.
Without this patch, EEH recovery does seem to work correctly for
at least some devices (I tested ethernet e1000), but fails to
recover others (the Emulex LightPulse LPFC, most notably).
Off the top of my head, I don't remember why some devices are
affected, but not others.
The PAPR indicates that the correct way to test for EEH is as
done in this patch; its not clear to me if this was in the PAPR
all along, or recently added; if it was there all along, its not
clear to me why this hadn't been fixed long ago. I suspect only
certain firmware levels are affected.
I've tested on one power4 and one power5; both have "old"
firmware (firmware dating back to not long after product
announce). It sure would be nice to test on more machines, huh?
I don't know how to quickly test on a broad spectrum of machines.
If this makes you nervous, I suppose this patch can wait for
the 2.6.21 series.
--linas
prev parent reply other threads:[~2007-01-26 22:53 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-26 20:55 [PATCH] pSeries: EEH improperly enabled for some Power4 systems Linas Vepstas
2007-01-26 22:30 ` Paul Mackerras
2007-01-26 22:53 ` Linas Vepstas [this message]
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