RE: How to remove DT support from a driver? (was Re: [PATCH v5 8/8] i2c: i2c-mlxbf.c: Update binding devicetree)

From: Asmaa Mnebhi
Date: Wed Sep 21 2022 - 16:17:56 EST


Thanks for your reply Wolfram. All customers using BlueField hardware need to install our internal Firmware (proprietary) before booting any customized OS so they will always use ACPI tables. So I think it is safe to remove it. Any feedback from the DT list would be greatly appreciated!

-----Original Message-----
From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Sent: Wednesday, September 21, 2022 4:02 PM
To: Asmaa Mnebhi <asmaa@xxxxxxxxxx>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; robh@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx; Khalil Blaiech <kblaiech@xxxxxxxxxx>
Subject: How to remove DT support from a driver? (was Re: [PATCH v5 8/8] i2c: i2c-mlxbf.c: Update binding devicetree)

Hi,

> I have a question for you and Wolfram, we don’t use device trees and
> are not planning to use device trees; we only use ACPI tables. But I
> think when Khalil submitted the first version of the i2c-mlxbf.c
> driver, it was requested from him to add devicetree support. Do you
> know why? Is it possible to remove the device tree support and so this
> doc? or is devicetree support a requirement regardless of the actual
> implementation?

The first version sent from Khalil to the public I2C mailing list already had DT bindings [1]. I don't see a sign of someone of the public list requesting DT bindings. Maybe it was company internal?

Technically, there is no requirement to support DT, especially since you have working ACPI. I don't know the process, though, of removing DT support. You would basically need to be sure that no user made use of the DT bindings introduced before. I don't know to what degree you can assume that.

Maybe the DT list has more to add here?

Happy hacking,

Wolfram

[1] http://patchwork.ozlabs.org/project/linux-i2c/list/?series=73827&state=*