From: Grant Edwards <grant.b.edwards@gmail.com>
To: linux-serial@vger.kernel.org
Subject: Re: New serial card development
Date: Tue, 23 Oct 2012 19:48:01 +0000 (UTC) [thread overview]
Message-ID: <k66s9h$4ir$2@ger.gmane.org> (raw)
In-Reply-To: 20121023202404.7e916cca@pyramind.ukuu.org.uk
On 2012-10-23, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
>> FWIW, in some products we're planning that will require support for
>> various industrial serial protocols, I'm leaning towards abandoning
>> the tty driver approach and writing a stand-alone character device
>> driver. The byte-stream oriented tty/line-discipline layer just
>> doesn't fit well when dealing with frame-oriented industrial protocols
>> that depend on things like 9th bit addressing and detecting
>> sub-millisecond inter-byte timeouts. When I add in the lack of
>> long-term stability in the tty API it seems like it might not be such
>> a bad idea to give up trying to make the tty abstraction fit a use
>> case that's just nothing like a teletype.
>
> Not unreasonable but we do need to cover it to some extent because there
> are a lot of 'multi-use' port types where you need to share the hardware
> or switch modes.
Agreed. Providing support for things like 9 bit mode, inter-byte
timeouts, arbitrary baud rates, half-duplex mode, and user-selectable
electrical interfaces (232/422/485/etc.) in the standard tty API would
be a good thing. Half-duplex mode (sometimes called RS485 mode) and
arbitrary baud rate are great recent additions.
> Although we don't use it that way its not entirely accidental that the
> tty buffer code supports chains of buffers with lengths 8)
Thanks, that's good to know.
--
Grant Edwards grant.b.edwards Yow! I can't decide which
at WRONG TURN to make first!!
gmail.com I wonder if BOB GUCCIONE
has these problems!
next prev parent reply other threads:[~2012-10-23 19:48 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-09 18:43 New serial card development Matt Schulte
2012-10-14 9:37 ` Theodore Ts'o
2012-10-15 19:08 ` Matt Schulte
2012-10-15 23:26 ` Alan Cox
2012-10-16 2:32 ` Theodore Ts'o
2012-10-17 20:24 ` Matt Schulte
2012-10-19 21:21 ` Theodore Ts'o
2012-10-23 16:27 ` Matt Schulte
2012-10-23 16:31 ` Matt Schulte
2012-10-23 18:38 ` Greg KH
2012-10-29 20:04 ` Matt Schulte
2012-10-31 21:55 ` Matt Schulte
2012-11-01 22:03 ` Matt Schulte
2012-11-01 22:26 ` Alan Cox
2012-11-02 18:47 ` Matt Schulte
2012-11-02 20:21 ` Alan Cox
2012-10-23 18:06 ` Grant Edwards
2012-10-23 18:26 ` Alan Cox
2012-10-23 18:45 ` Grant Edwards
2012-10-23 19:16 ` Greg KH
2012-10-23 19:42 ` Grant Edwards
2012-10-23 20:10 ` Greg KH
2012-10-23 19:24 ` Alan Cox
2012-10-23 19:48 ` Grant Edwards [this message]
2012-10-23 20:31 ` Theodore Ts'o
2012-10-23 20:41 ` Grant Edwards
[not found] ` <CAJp1Oe6k7NWqdbYkJnd787JiT55-wSbG+tX1tP7Cy-oPShdVaA@mail.gmail.com>
2012-10-17 20:23 ` Matt Schulte
2012-10-17 21:53 ` Alan Cox
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