From: Oliver Neukum <oneukum@suse.com>
To: Alex Henrie <alexhenrie24@gmail.com>,
Greg KH <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, Johan Hovold <johan@kernel.org>,
vojtech@suse.cz
Subject: Re: ttyACM versus ttyUSB
Date: Mon, 13 Oct 2025 11:28:59 +0200 [thread overview]
Message-ID: <194258bf-e78c-46b8-8229-3b019f2b8ab0@suse.com> (raw)
In-Reply-To: <CAMMLpeQvb1SJ=_kC+N1pGHkh36yrORJq+Der7fDzPj_urzefow@mail.gmail.com>
On 12.10.25 21:01, Alex Henrie wrote:
> I did notice that the ACM protocol has no way to set the baud rate or
> read the CTS line and I wondered if those limitations were the reason
> for keeping its driver separate. Today there are ttyUSB drivers that
> likewise have limitations on the baud rate and the flow control lines
> (some are even based on ACM), but they weren't around in 1999, so I
> can see how the difference in capabilities would have been another
> motivation for the difference in naming conventions.
You could argue that ACM is intended to be a driver for a _modem_ ,
not a serial line. In principle we are trying to propagate a layering
violation that is so old that we no longer see it as a violation.
Regards
Oliver
next prev parent reply other threads:[~2025-10-13 9:29 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-12 5:00 ttyACM versus ttyUSB Alex Henrie
2025-10-12 6:07 ` Greg KH
2025-10-12 15:55 ` Alex Henrie
2025-10-12 16:21 ` Greg KH
2025-10-12 19:01 ` Alex Henrie
2025-10-12 19:53 ` Greg KH
2025-10-12 22:40 ` Alex Henrie
2025-10-13 9:28 ` Oliver Neukum [this message]
2025-10-13 10:47 ` Vojtech Pavlik
2025-10-13 15:42 ` Alex Henrie
2025-10-13 16:14 ` Greg KH
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