[Skiboot] [PATCH 1/2] PHB3: Retry fundamental reset

[Stewart Smith]

Gavin Shan <gwshan at linux.vnet.ibm.com> writes:
> When issuing fundamental reset on below IPR adapter that seats
> behind root complex, there is 50% possibility that the link
> fails to come up after the reset. In that case, the adapter's
> config space is blocked and it's not usable.
>
>    host# lspci -ns 0004:01:00.0
>    0004:01:00.0 0104: 1014:034a (rev 01)
>    host# lspci -s 0004:01:00.0
>    0004:01:00.0 RAID bus controller: IBM PCI-E IPR SAS Adapter
>                 (ASIC) (rev 01)
>
> This introduces another PHB3 state (PHB3_STATE_FRESET_START)
> allowing to redo fundamental reset if the link doesn't come up
> in time at the first attempt, to improve the robustness of PHB's
> fundamental reset. If the link comes up after the first reset,
> the 2nd reset won't be issued at all.

Thanks,
as discussed on IRC, merged into a tree for skiboot-5.1.7 (and also
master).

In the process of doing a 5.1.6 that's just going through final testing.