From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Adam Borowski <kilobyte@angband.pl>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>,
linux-serial@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Donald Buczek <buczek@molgen.mpg.de>
Subject: Re: Device to write to all (serial) consoles
Date: Sat, 3 Aug 2019 15:55:37 +0200 [thread overview]
Message-ID: <20190803135537.GA1743@kroah.com> (raw)
In-Reply-To: <20190803132323.GB6703@angband.pl>
On Sat, Aug 03, 2019 at 03:23:23PM +0200, Adam Borowski wrote:
> 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).
You can get that information from the symlinks in /dev/serial/ which
udev creates.
next prev parent reply other threads:[~2019-08-03 13:55 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-02 13:23 Device to write to all (serial) consoles Paul Menzel
2019-08-02 16:02 ` Greg Kroah-Hartman
2019-08-02 19:59 ` Paul Menzel
2019-08-03 6:46 ` Greg Kroah-Hartman
2019-08-03 13:23 ` Adam Borowski
2019-08-03 13:55 ` Greg Kroah-Hartman [this message]
2019-08-03 15:15 ` Adam Borowski
2019-08-08 14:52 ` Enrico Weigelt, metux IT consult
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