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From:   Heiko Thiery <heiko.thiery@gmail.com>
Date:   Thu, 30 Sep 2021 20:52:33 +0200
Message-ID: <CAEyMn7YbYAUvxEgKDB4x4AGomhBeuBDj71b2LuCs1A2emToU0w@mail.gmail.com>
Subject: Re: [PATCH 8/8] arm64: dts: imx8mm-kontron: Leave reg_vdd_arm always
 powered on
To:     Frieder Schrempf <frieder@fris.de>
Cc:     devicetree@vger.kernel.org,
        Frieder Schrempf <frieder.schrempf@kontron.de>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Rob Herring <robh+dt@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Shawn Guo <shawnguo@kernel.org>, stable@vger.kernel.org,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Pengutronix Kernel Team <kernel@pengutronix.de>
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Hi Frieder,

Am Do., 30. Sept. 2021 um 17:57 Uhr schrieb Frieder Schrempf <frieder@fris.de>:
>
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>
> When the cpufreq driver is enabled, the buck2 regulator is kept powered on
> by the dependency between the CPU nodes with 'cpu-supply' set. Without the
> cpufreq driver the kernel will power off the regulator as it doesn't see
> any users. This is obviously not what we want, therefore keep the regulator
> powered on in any case.
>
> Reported-by: Heiko Thiery <heiko.thiery@gmail.com>
> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>

Tested-by: Heiko Thiery <heiko.thiery@gmail.com>

> ---
>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> index 213014f59b46..c3418d263eb4 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> @@ -105,6 +105,7 @@ reg_vdd_arm: BUCK2 {
>                                 regulator-min-microvolt = <850000>;
>                                 regulator-max-microvolt = <950000>;
>                                 regulator-boot-on;
> +                               regulator-always-on;
>                                 regulator-ramp-delay = <3125>;
>                                 nxp,dvs-run-voltage = <950000>;
>                                 nxp,dvs-standby-voltage = <850000>;
> --
> 2.33.0
>