[Skiboot] [PATCH] fsp: return OPAL_BUSY_EVENT on failure sending FSP_CMD_POWERDOWN_NORM

[Stewart Smith]

Vasant Hegde <hegdevasant at linux.vnet.ibm.com> writes:
>> --- a/platforms/ibm-fsp/common.c
>> +++ b/platforms/ibm-fsp/common.c
>> @@ -223,7 +223,7 @@ int64_t ibm_fsp_cec_power_down(uint64_t request)
>>  	printf("FSP: Sending shutdown command to FSP...\n");
>
> We may endup filling OPAL console with above message as kernel will repeatedly 
> makes shutdown call.

Yeah, at least that's not user visible though?

>>  	if (fsp_sync_msg(fsp_mkmsg(FSP_CMD_POWERDOWN_NORM, 1, request), true))
>
> How about changing this to fsp_queue_msg?  Even in shutdown path we will be able 
> to queue message and send it to FSP after R/R completes.

If we have a pending firmware update though, we'll have all CPUs in OPAL
with interrupts off, so we do have to go and run pollers to have a
chance of making forward progress. Even though we'd never apply the
update due to R/R, (not that I think we've ever tested this exact
scenario), we would still go down that code path in the kernel.

In that case, we'd still have to return OPAL_BUSY_EVENT so we could
reconnect and process the queued message, so it really wouldn't make
much of a difference (in fact, we'd have to keep track on if we've
queued it or not).

-- 
Stewart Smith
OPAL Architect, IBM.