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Date: Mon, 22 Aug 2016 22:35:56 +0100
From: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
To: Marcel Holtmann <marcel@holtmann.org>
Cc: Arnd Bergmann <arnd@arndb.de>, Rob Herring <robh@kernel.org>,
        Greg
 Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.com>, Sebastian Reichel <sre@kernel.org>,
        Pavel Machek <pavel@ucw.cz>, Peter
 Hurley <peter@hurleysoftware.com>,
        NeilBrown <neil@brown.name>,
        "Dr . H .
 Nikolaus Schaller" <hns@goldelico.com>,
        Linus Walleij
 <linus.walleij@linaro.org>,
        "open list:BLUETOOTH DRIVERS"
 <linux-bluetooth@vger.kernel.org>,
        "linux-serial@vger.kernel.org"
 <linux-serial@vger.kernel.org>,
        "linux-kernel@vger.kernel.org"
 <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 0/3] UART slave device bus
Message-ID: <20160822223556.0127ae6f@lxorguk.ukuu.org.uk>
In-Reply-To: <FAD4CEF6-93F4-41D1-915E-823867F740F7@holtmann.org>
References: <20160818011445.22726-1-robh@kernel.org>
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	<CAL_JsqL1s9QTc+xVXafcHmyiH+6Yy0Ded+JbeYhTtYNxLtWREg@mail.gmail.com>
	<2775954.hrE2UdODgU@wuerfel>
	<20160822164533.688a6aec@lxorguk.ukuu.org.uk>
	<FAD4CEF6-93F4-41D1-915E-823867F740F7@holtmann.org>
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List-ID: <linux-bluetooth.vger.kernel.org>

> I now wonder if we can not just turn the ldisc into a bus. So we have a ldisc bus that exposes devices that have no business of having a userspace /dev/ttyX exposed. And our Bluetooth UART support just turns into a ldisc driver on the ldisc bus.

The ldisc and tty have the wrong object lifetime for a bus, but you can
put the tty_port objects onto the bus, and it is those you need to
instantiate the stack.

The port exists for hardware lifetime, the tty and ldisc exist only while
the port is "up".

Alan