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Date:   Wed, 10 Oct 2018 13:20:48 -0700
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Subject: Re: Insanely high baud rates
To:     Alan Cox <gnomes@lxorguk.ukuu.org.uk>
CC:     linux-serial@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.com>, Johan Hovold <johan@kernel.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>
From:   hpa@zytor.com
Message-ID: <16D6AB22-697E-498C-A5B2-3AD90B567E86@zytor.com>
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On October 10, 2018 1:17:17 PM PDT, Alan Cox <gnomes@lxorguk.ukuu.org.uk> wrote:
>On Tue, 9 Oct 2018 12:19:04 -0700
>"H. Peter Anvin" <hpa@zytor.com> wrote:
>
>> [Resending to a wider audience]
>> 
>> In trying to get the termios2 interface actually implemented in
>glibc,
>> the question came up if we will ever care about baud rates in excess
>of
>> 4 Gbps, even in the relatively remote future.
>
>Even RS485 at 4MBits involves deep magic. I think we are fairly safe.
>Not
>only that but our entire tty layer isn't capable of sustaining anything
>even remotely in that range.
>
>I think its non issue.
>
>Alan

I'm mostly wondering if it is worth future-proofing for new transports. It sounds like we can have a consensus on leaving the upper 4 bits of the speed fields reserved, but leave the details of implementation for the future?
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