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From: "Oliver O'Halloran" <oohall@gmail.com>
Date: Wed, 24 Nov 2021 22:57:13 +1100
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Subject: Re: [PATCH] powerpc/eeh: Delay slot presence check once driver is
 notified about the pci error.
To: Mahesh J Salgaonkar <mahesh@linux.ibm.com>
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On Wed, Nov 24, 2021 at 7:45 PM Mahesh J Salgaonkar
<mahesh@linux.ibm.com> wrote:
>
> No it doesn't. We will still do a presence check before the recovery
> process starts. This patch moves the check after notifying the driver to
> stop active I/O operations. If a presence check finds the device isn't
> present, we will skip the EEH recovery. However, on a surprise hotplug,
> the user will see the EEH messages on the console before it finds there
> is nothing to recover.

Suppressing the spurious EEH messages was part of why I added that
check in the first place. If you want to defer the presence check
until later you should move the stack trace printing, etc to after
we've confirmed there are still devices present. Considering the
motivation for this patch is to avoid spurious warnings from the
driver I don't think printing spurious EEH messages is much of an
improvement.

The other option would be returning an error from the pseries hotplug
driver. IIRC that's what pnv_php / OPAL does if the PHB is fenced and
we can't check the slot presence state.