powerpc/eeh: Enable IO path on permanent error

[Michael Ellerman]

On Thu, 2017-01-05 at 23:39:49 UTC, Gavin Shan wrote:
> We give up recovery on permanent error, simply shutdown the affected
> devices and remove them. If the devices can't be put into quiet state,
> they spew more traffic that is likely to cause another unexpected EEH
> error. This was observed on "p8dtu2u" machine:
> 
>    0002:00:00.0 PCI bridge: IBM Device 03dc
>    0002:01:00.0 Ethernet controller: Intel Corporation \
>                 Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
>    0002:01:00.1 Ethernet controller: Intel Corporation \
>                 Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
>    0002:01:00.2 Ethernet controller: Intel Corporation \
>                 Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
>    0002:01:00.3 Ethernet controller: Intel Corporation \
>                 Ethernet Controller X710/X557-AT 10GBASE-T (rev 02)
> 
> On P8 PowerNV platform, the IO path is frozen when shutdowning the
> devices, meaning the memory registers are inaccessible. It is why
> the devices can't be put into quiet state before removing them.
> This fixes the issue by enabling IO path prior to putting the devices
> into quiet state.
> 
> Link: https://github.com/open-power/supermicro-openpower/issues/419
> Reported-by: Pridhiviraj Paidipeddi <ppaidipe at linux.vnet.ibm.com>
> Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
> Acked-by: Russell Currey <ruscur at russell.cc>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/387bbc974f6adf91aa635090f73434

cheers