From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Thu, 16 Feb 2017 14:31:38 +0100
Subject: [PATCH 4/5] sprd_serial: switch comptible string to sc-uart
In-Reply-To: <1487063952-7113-5-git-send-email-chunyan.zhang@spreadtrum.com>
References: <1487063952-7113-1-git-send-email-chunyan.zhang@spreadtrum.com>
 <1487063952-7113-5-git-send-email-chunyan.zhang@spreadtrum.com>
Message-ID: <1761969.45NG6Q1Iyc@wuerfel>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tuesday, February 14, 2017 5:19:11 PM CET Chunyan Zhang wrote:
>  static const struct of_device_id serial_ids[] = {
> -       {.compatible = "sprd,sc9836-uart",},
> +       {.compatible = "sprd,sc-uart",},
>         {}

We really need this to be specific, in case Spreadtrum ever
makes a slightly different UART that is not 100% compatible
with this one. Also, you can't remove the string you already have,
only add to it.

Normally when you have a new chip that is compatible with one
we already have a driver for, we mark the device as compatible
with the old one and avoid having to change the driver, e.g.

	compatible = "sprd,sc9995-uart", "sprd,sc9836-uart";

This way, the driver could later be changed to handle anything
that is compatible with sc9995 differently from sc9836, but
by default it would match the original string.

	Arnd