[Skiboot] [PATCH V2] hw/fsp: Do not queue SP and SPCN class messages during reset/reload

[Stewart Smith]

Ananth N Mavinakayanahalli <ananth at linux.vnet.ibm.com> writes:
> During FSP R/R, the FSP is inaccessible and will lose state. Messages to the
> FSP are generally queued for sending later.
>
> It does seem like the FSP fails to process any subseuqent messages of certain
> classes (SP info -- ipmi) if it receives queued mbox messages it isn't expecting.
>
> In certain other cases (sensors), the FSP driver returns a default code (async
> completion) even though there is no known bound from the time of this error
> return to the actual data being available. The kernel driver keeps waiting
> leading to soft-lockup on the host side.
>
> Mitigate both these (known) cases by returning OPAL_BUSY so the host driver
> knows to retry later.
>
> With this change, the sensors command works fine when the FSP comes back.
>
> This version also resolves the remaining IPMI issues
>
>
> Signed-off-by: Ananth N Mavinakayanahalli <ananth at linux.vnet.ibm.com>
> Tested-by: Pridhiviraj Paidipeddi <ppaidipe at linux.vnet.ibm.com>

Thanks, merged to master as of 4940b8148640c06e139aec8c6d0370af7dd3b184

cherry picked into 5.4.x as of a6d5bc107e76123440d60a05698c151084604180
cherry picked into 5.3.x as of d18986fbc4c2d8ec5495b063cafbd1686403293a

-- 
Stewart Smith
OPAL Architect, IBM.