[Skiboot] [PATCH 01/14] phb4: Only clear some PHB config space registers on errors

[Stewart Smith]

Michael Neuling <mikey at neuling.org> writes:
> Currently on error we clear the entire PHB config space.  This is a
> problem as the PCIe Maximum Payload Size (MPS) negotiation may have
> already occurred. Clearing MPS in the PHB back to a default of 128
> bytes will result an error for a device which already has a larger MPS
> configured.
>
> This will manifest itself as error due to a malformed TLP packet. ie.
>   phbPblErrorStatus bit 41  = "Malformed TLP error"
> This has been seen after kexec on with some adapters.
>
> This fixes the problem by only clearing a subset of registers on a phb
> error.
>
> Reported-by: Rob Lippert <rlippert at google.com>
> Signed-off-by: Michael Neuling <mikey at neuling.org>
> ---
>  hw/phb4.c | 51 ++++++++++++++++++++++++++++++++-------------------
>  1 file changed, 32 insertions(+), 19 deletions(-)

Thanks! Series merged to master as of
2a95a2db72155b270dc568d257c2fce5f459e17a

I'll put up a PR for updating it in op-build today, but it may not pass
through all the CI before beer o'clock.

-- 
Stewart Smith
OPAL Architect, IBM.