Re: [PATCH v6 07/11] arm64: dts: imx8qxp-mek: Add supports-clkreq property to PCIe M.2 port

Frank Li
2025-10-31T19:40:32Z

On Wed, Oct 15, 2025 at 11:04:24AM +0800, Richard Zhu wrote:
> According to PCIe r6.1, sec 5.5.1.
>
> The following rules define how the L1.1 and L1.2 substates are entered:
> Both the Upstream and Downstream Ports must monitor the logical state of
> the CLKREQ# signal.
>
> Typical implement is using open drain, which connect RC's clkreq# to
> EP's clkreq# together and pull up clkreq#.
>
> imx8qxp-mek matches this requirement, so add supports-clkreq to allow
> PCIe device enter ASPM L1 Sub-State.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

shawn: I posted it as richard at imx8qxp dts patches, you can pick this one
with other part together.

> arch/arm64/boot/dts/freescale/imx8qxp-mek.dts | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8qxp-mek.dts b/arch/arm64/boot/dts/freescale/imx8qxp-mek.dts
> index 7b03374455410..9c457c2236a61 100644
> --- a/arch/arm64/boot/dts/freescale/imx8qxp-mek.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8qxp-mek.dts
> @@ -631,6 +631,7 @@ &pcie0 {
> pinctrl-names = "default";
> reset-gpios = <&lsio_gpio4 0 GPIO_ACTIVE_LOW>;
> vpcie-supply = <&reg_pcieb>;
> + supports-clkreq;
> status = "okay";
> };
>
> --
> 2.37.1
>