linux-kernel - Re: [PATCH 04/15] powerpc/powernv: opal-kmsg use flush fallback from console code

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Message-ID: <87wowfbvm0.fsf@concordia.ellerman.id.au>
Date:   Mon, 07 May 2018 20:36:39 +1000
From:   Michael Ellerman <mpe@...erman.id.au>
To:     Nicholas Piggin <npiggin@...il.com>
Cc:     linuxppc-dev@...ts.ozlabs.org, Jiri Slaby <jslaby@...e.com>,
        linux-kernel@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [PATCH 04/15] powerpc/powernv: opal-kmsg use flush fallback from console code

Nicholas Piggin <npiggin@...il.com> writes:
> On Fri, 04 May 2018 15:16:37 +1000
> Michael Ellerman <mpe@...erman.id.au> wrote:
>> Nicholas Piggin <npiggin@...il.com> writes:
>> > Use the more refined and tested event polling loop from opal_put_chars
>> > as the fallback console flush in the opal-kmsg path. This loop is used
>> > by the console driver today, whereas the opal-kmsg fallback is not
>> > likely to have been used for years.
>> >
>> > Use WARN_ONCE rather than a printk when the fallback is invoked to
>> > prepare for moving the console flush into a common function.  
>> 
>> Do we want to add a WARN in that path? If we're panicking things might
>> get worse if we WARN (which takes a trap).
>
> True, probably a good idea not to... oh there's a printk_once so
> that'll work nicely.

Cool.

I have this series in a tree so you can send me an incremental diff if
it's reasonably small.

cheers