[Skiboot] [PATCH] Add OPAL_CONSOLE_FLUSH to the OPAL API

[Stewart Smith]

Russell Currey <ruscur at russell.cc> writes:
>> > +OPAL_CONSOLE_FLUSH
>> > +------------------
>> > +
>> > +Parameters:
>> > +	none
>> 
>> Should same paramter as OPAL_CONSOLE_READ/WRITE, which accepts a
>> term_number parameter. We may want a simple way to say "just the one
>> that's actually the OPAL console dammit" - maybe ~0 as term_number?
>> 
>> > +
>> > +Returns:
>> > +	none
>> 
>> Should return OPAL_SUCCESS and as mentioned above OPAL_BUSY if buffer
>> not completely flushed (actually... come to think of it, maybe
>> OPAL_PARTIAL is what we want there).
>> 
>> Even though OPAL_CONSOLE_WRITE is currently synchronous and all that,
>> let's not limit what we specify the API to be.
>> 
> Okay, so how about:
>
>  - OPAL_PARAMETER if the term_number is invalid
>  - OPAL_UNSUPPORTED if the console type doesn't support implement flush()
>  - OPAL_BUSY if there's still more to flush

OPAL_PARTIAL is probably what we want rather than BUSY (although maybe
BUSY if we can't flush anything, then in theory OS could just give up
waiting at some point - especially in the scenario when it does want to
reboot).

So let's have OPAL_BUSY when nothing was flushed, OPAL_PARTIAL when we
at least flushed something and are making forward progress.

>  - OPAL_SUCCESS if the buffer is now fully flushed