Re: [Gta04-owner] [PATCH 0/3] tty slave device support - version 3.

From: "Dr. H. Nikolaus Schaller" <hns@goldelico.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: List for communicating with real GTA04 owners 
	<gta04-owner@goldelico.com>, NeilBrown <neil@brown.name>,
	Mark Rutland <mark.rutland@arm.com>,
	One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sebastian Reichel <sre@kernel.org>,
	Grant Likely <grant.likely@linaro.org>,
	Jiri Slaby <jslaby@suse.cz>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [Gta04-owner] [PATCH 0/3] tty slave device support - version 3.
Date: Wed, 6 May 2015 13:50:29 +0200	[thread overview]
Message-ID: <A2594559-CA92-40C2-A06A-AC2483E85CB1@goldelico.com> (raw)
In-Reply-To: <20150506092738.GB4508@amd>

Hi Pavel,

Am 06.05.2015 um 11:27 schrieb Pavel Machek <pavel@ucw.cz>:

> On Wed 2015-05-06 07:19:31, Dr. H. Nikolaus Schaller wrote:
>> Hi Peter,
>> 
>> Am 05.05.2015 um 21:54 schrieb Peter Hurley <peter@hurleysoftware.com>:
>> 
>>> Hi Neil,
>>> 
>>> On 03/18/2015 01:58 AM, NeilBrown wrote:
>>>> here is version 3 of support for tty-slaves.
>>> 
>>> Is there a v4 of this that I missed?
>> 
>> We did have a lengthy discussion about [PATCH 3/3] how to best (1)
>> represent the slave device in the device tree but as far as I am concerned,
>> I do not see that we have a consensus (2) and the device tree maintainers
>> have no comments or clear guidelines so far.
> 
> Yes. Everyone and their dog disagrees

What a wonderful argument…
I still ask myself who the dog is.

> with Nikolaus, who is playing
> devil's advocate

I hope you don't think that Linux users are devils…

No, I am not playing devil’s advocate (which would imply that I am doing this
for fun to tease the dog), but I feel I have to be the advocate of future board
designers who want to easily import an existing board DT and overwrite device
tree nodes to describe design changes, i.e. what slave device is connected to
which uart.

At least in this regard, the alternatives are really differently easy to handle.

And, the alternatives have some influence how a tty driver and a slave device
driver is designed. So that is for me the root question, before discussing (some)
implementation details.

Because it is not resolved in a way that convinces me (and future board DT
designers), I bring it up again and again. Even if you and some dog apparently
disagree.

> here, so we clearly have to get confirmation from
> device tree maintainers. And when they disagree with him, we'll need
> to get concensus from Linus, too...
> 									Pavel

BR,
Nikolaus