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Re: [Xen-devel] [PATCH] Default serial console to BAUD_AUTO

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] Default serial console to BAUD_AUTO
From: John Levon <john.levon@xxxxxxx>
Date: Mon, 24 Sep 2007 18:58:02 +0100
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On Mon, Sep 24, 2007 at 08:43:30AM +0100, Keir Fraser wrote:

> >> If we do this we should remove com1 from the default console= string.
> >> Otherwise we waste time on serial output for many users who have nothing
> >> connected (currently a com1= line has to be specified for serial output to
> >> be enabled on Xen/x86). console=vga is probably what most people expect by
> >> default?
> > 
> > The default setting is "com1,vga". However, the last setting is always 
> > taken,
> > and overrides all others, so this is exactly equal to "vga". This should
> > probably be cleaned up, but I don't think my patch changes anything in this
> > regard.
> I would agree, if your statement was true. Which it's not.

Indeed, this has changed in xen-unstable compared to 3.0.4, my apologies. So
with my patch you'll automatically get serial console output in xen-unstable,
regardless of console=com1

When you say "waste time", what exactly do you mean? Are you concerned about
printk() performance? Isn't this only debug and early boot? It seems to me that
getting such serial console output by default is pretty useful.

Otherwise, I'm fine with remove com1 from opt_console, as it matches current


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