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Date:   Thu, 12 Dec 2019 10:23:19 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Petr Mladek <pmladek@suse.com>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        linux-kernel@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        AlekseyMakarov <aleksey.makarov@linaro.org>
Subject: Re: [RFC/PATCH] printk: Fix preferred console selection with
 multiple matches
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On (19/12/11 10:17), Petr Mladek wrote:
> And this would exactly happen as pointed out by Sergey. match() does
> also some setup operations. I would be scared to call them twice.
> 
> > This looks indeed a lot more invasive. Is there any reason why what I
> > propose wouldn't work as a first patch that can easily be backported ?
> 
> Your solution is not acceptable because it might cause calling
> match() more times.
> 
> The reverse search of list of console does not work for ttySX
> consoles because the number is omitted when matching. And the messages
> will appear only on the first matched serial console. There is
> a paragraph about this in the commit message of my patch.

A fast path for preferred_console match()/setup() sounds like
something that may work. There won't be double setup()-s and
we scan console list in the same direction. We just have
separate match()/setup() for preferred_console. Do you think
this won't do the trick?

	-ss