From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Johan Hovold <johan@kernel.org>
Cc: Jiri Slaby <jirislaby@kernel.org>,
"Mychaela N . Falconia" <falcon@freecalypso.org>,
linux-serial@vger.kernel.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/7] tty: add flag to suppress ready signalling on open
Date: Wed, 9 Dec 2020 15:30:33 +0100 [thread overview]
Message-ID: <X9Dficb8sQGRut+S@kroah.com> (raw)
In-Reply-To: <20201202113942.27024-1-johan@kernel.org>
On Wed, Dec 02, 2020 at 12:39:35PM +0100, Johan Hovold wrote:
> This series adds a new NORDY port flag to suppress raising the
> modem-control lines on open to signal DTE readiness.
>
> This can be used to implement a NORDY termios control flag to complement
> HUPCL, which controls lowering of the modem-control lines on final
> close.
>
> Initially drivers can export the flag through sysfs, which also allows
> control over the lines on first open. Such an interface is implemented
> for serial core and USB serial.
>
> The motivation for this is to allow for applications where the DTR and
> RTS lines are used for non-standard purposes (e.g. generating power-on
> and reset pulses) to open the port without undesirable side effects.
>
> The final patches enables this flag by default for such a USB serial
> device.
>
> Other examples include HAM-radio devices where DTR and RTS is used for
> push-to-talk and continuous-wave control and various Arduino boards
> which are reset on open unless a jumper is physically removed.
>
> Greg, are you ok we me taking this through my tree? I'm planning on some
> follow ups to the ftdi driver and the tty/serial changes are fairly
> self-contained.
>
> Also let me know if you prefer to hold this off for 5.12. The change is
> minimal, self-contained and low-risk, but it is a new interface and late
> in the release cycle as Andy pointed out.
I took the first 2 patches now, that was easy :)
I think we need more review for the rest of the series. This does
change the way serial ports work in a non-traditional way (i.e. using
sysfs instead of terminal settings). So I want to get a bunch of people
to agree that this is ok to do things this way now before taking this
new user-visible api.
thanks,
greg k-h
next prev parent reply other threads:[~2020-12-09 14:30 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 11:39 [PATCH v2 0/7] tty: add flag to suppress ready signalling on open Johan Hovold
2020-12-02 11:39 ` [PATCH v2 1/7] tty: use assign_bit() in port-flag accessors Johan Hovold
2020-12-02 11:39 ` [PATCH v2 2/7] tty: use const parameters " Johan Hovold
2020-12-02 11:39 ` [PATCH v2 3/7] tty: add port flag to suppress ready signalling on open Johan Hovold
2020-12-02 11:39 ` [PATCH v2 4/7] serial: core: add sysfs attribute " Johan Hovold
2020-12-02 11:39 ` [PATCH v2 5/7] USB: serial: " Johan Hovold
2020-12-02 11:39 ` [PATCH v2 6/7] USB: serial: ftdi_sio: pass port to quirk port_probe functions Johan Hovold
2020-12-02 11:39 ` [PATCH v2 7/7] USB: serial: ftdi_sio: add support for FreeCalypso DUART28C adapter Johan Hovold
2020-12-02 18:07 ` [PATCH v2 0/7] tty: add flag to suppress ready signalling on open Mychaela Falconia
2020-12-03 9:21 ` Johan Hovold
2020-12-09 14:30 ` Greg Kroah-Hartman [this message]
2020-12-09 15:10 ` Johan Hovold
2020-12-09 22:49 ` Mychaela Falconia
2020-12-10 9:06 ` Greg Kroah-Hartman
2020-12-10 10:41 ` Maarten Brock
2020-12-10 10:50 ` Greg Kroah-Hartman
2020-12-10 12:05 ` Maarten Brock
2020-12-10 13:01 ` Greg Kroah-Hartman
2020-12-10 18:59 ` Mychaela Falconia
2020-12-11 8:46 ` Jiri Slaby
2020-12-11 16:08 ` Greg Kroah-Hartman
2020-12-11 15:51 ` Maarten Brock
2020-12-11 16:08 ` Greg Kroah-Hartman
2020-12-14 14:21 ` Johan Hovold
2020-12-18 18:03 ` Mychaela Falconia
2021-01-07 15:25 ` Greg Kroah-Hartman
[not found] ` <YBPxG+i/ZLP8/wg1@hovoldconsulting.com>
2021-01-31 0:18 ` Mychaela Falconia
2021-01-31 5:24 ` Greg Kroah-Hartman
2020-12-11 10:46 ` Johan Hovold
2020-12-11 10:41 ` Johan Hovold
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