Re: [PATCH 4/5] sprd_serial: switch comptible string to sc-uart

From: Arnd Bergmann
Date: Thu Feb 16 2017 - 08:32:41 EST

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.