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Date:   Sat, 3 Aug 2019 15:23:23 +0200
From:   Adam Borowski <kilobyte@angband.pl>
To:     Paul Menzel <pmenzel@molgen.mpg.de>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
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Subject: Re: Device to write to all (serial) consoles
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On Fri, Aug 02, 2019 at 09:59:06PM +0200, Paul Menzel wrote:
> On 02.08.19 18:02, Greg Kroah-Hartman wrote:
> > On Fri, Aug 02, 2019 at 03:23:08PM +0200, Paul Menzel wrote:
> > > On a lot of devices, like servers, you have more than one serial console,
> > > and you do not always know, how they are numbered. Therefore, we start a
> > > console on ttyS0 and ttyS1.
> 
> Because the cable is always connected to the port on the back side, and
> sometimes the port in the front has ID 0, and the one in the back 1, and
> other times vice versa. We do not want to track that, and it would be
> convenient to just write to both ports.

Sounds like an XY problem then: what you want is not writing to all ports,
but to have the port assignments stable (see also: disk device reordering).


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