Re: [PATCH v7 3/3] arm64: dts: reset: add microchip sparx5 switch reset driver

From: Rob Herring <robh@kernel.org>
To: Steen Hegelund <steen.hegelund@microchip.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>,
	Andrew Lunn <andrew@lunn.ch>,
	Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Gregory Clement <gregory.clement@bootlin.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org
Subject: Re: [PATCH v7 3/3] arm64: dts: reset: add microchip sparx5 switch reset driver
Date: Mon, 8 Mar 2021 12:59:34 -0700	[thread overview]
Message-ID: <20210308195934.GA2855503@robh.at.kernel.org> (raw)
In-Reply-To: <20210303081158.684532-4-steen.hegelund@microchip.com>

On Wed, Mar 03, 2021 at 09:11:58AM +0100, Steen Hegelund wrote:
> This provides reset driver support for the Microchip Sparx5 PCB134 and
> PCB135 reference boards.

This still looks like an incompatible change with no explanation.

What happens on an old kernel that expects "microchip,sparx5-chip-reset" 
and doesn't understand "microchip,sparx5-switch-reset"?

> 
> Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
> ---
>  arch/arm64/boot/dts/microchip/sparx5.dtsi | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> index 380281f312d8..dc3ada5cf9fc 100644
> --- a/arch/arm64/boot/dts/microchip/sparx5.dtsi
> +++ b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> @@ -132,9 +132,12 @@ mux: mux-controller {
>  			};
>  		};
>  
> -		reset@611010008 {
> -			compatible = "microchip,sparx5-chip-reset";
> +		reset: reset-controller@611010008 {
> +			compatible = "microchip,sparx5-switch-reset";
>  			reg = <0x6 0x11010008 0x4>;
> +			reg-names = "gcb";
> +			#reset-cells = <1>;
> +			cpu-syscon = <&cpu_ctrl>;
>  		};
>  
>  		uart0: serial@600100000 {
> -- 
> 2.30.1
> 