Re: [PATCH 14/14] ARM: dts: imx6sx-sdb-mqs: remove empty pinctrl-0

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] ARM: dts: imx6sx-sdb-mqs: inherited sai1 pinctrl-0 conflicts with audmux
--

commit 7833db678f76ab4ca49bd301d79848b89980d394
Author: Frank Li <Frank.Li@nxp.com>

ARM: dts: imx6sx-sdb-mqs: remove empty pinctrl-0

This commit removes the empty pinctrl-0 property from the sai1 node in
imx6sx-sdb-mqs.dts to resolve a dtbs_check schema validation warning.

> diff --git a/arch/arm/boot/dts/nxp/imx/imx6sx-sdb-mqs.dts b/arch/arm/boot/dts/nxp/imx/imx6sx-sdb-mqs.dts
> index a4ab2d3e960c4..82ae475a018e1 100644
> --- a/arch/arm/boot/dts/nxp/imx/imx6sx-sdb-mqs.dts
> +++ b/arch/arm/boot/dts/nxp/imx/imx6sx-sdb-mqs.dts
> @@ -33,7 +33,6 @@ &mqs {
>  };
>  
>  &sai1 {
> -	pinctrl-0 = <>;
>  	status = "okay";
>  };
>  

[Severity: High]
Does removing pinctrl-0 = <>; here without using /delete-property/ cause
&sai1 to inherit pinctrl-0 = <&pinctrl_sai1>; from imx6sx-sdb.dtsi and
conflict with &audmux at probe time?

imx6sx-sdb-mqs.dts includes imx6sx-sdb.dts, which includes imx6sx-sdb.dtsi
where &sai1 and &audmux are defined as:

arch/arm/boot/dts/nxp/imx/imx6sx-sdb.dtsi:
    &audmux {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_audmux>;
        status = "okay";
    };
    ...
    &sai1 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_sai1>;
        status = "disabled";
    };

In imx6sx-sdb.dtsi, pinctrl_audmux and pinctrl_sai1 configure the same five
CSI pads:

    pinctrl_audmux: audmuxgrp {
        fsl,pins = <
            MX6SX_PAD_CSI_DATA00__AUDMUX_AUD6_TXC   0x130b0
            MX6SX_PAD_CSI_DATA01__AUDMUX_AUD6_TXFS  0x130b0
            MX6SX_PAD_CSI_HSYNC__AUDMUX_AUD6_TXD    0x120b0
            MX6SX_PAD_CSI_VSYNC__AUDMUX_AUD6_RXD    0x130b0
            MX6SX_PAD_CSI_PIXCLK__AUDMUX_MCLK       0x130b0
        >;
    };
    ...
    pinctrl_sai1: sai1grp {
        fsl,pins = <
            MX6SX_PAD_CSI_DATA00__SAI1_TX_BCLK      0x130b0
            MX6SX_PAD_CSI_DATA01__SAI1_TX_SYNC      0x130b0
            MX6SX_PAD_CSI_HSYNC__SAI1_TX_DATA_0     0x120b0
            MX6SX_PAD_CSI_VSYNC__SAI1_RX_DATA_0     0x130b0
            MX6SX_PAD_CSI_PIXCLK__AUDMUX_MCLK       0x130b0
        >;
    };

In MQS mode, sai1 routes audio internally to the MQS block (&mqs, which uses
pinctrl_mqs on SD2_CLK and SD2_CMD) rather than using external SAI1 pins.
Commit 73691f21e211 ("ARM: dts: imx6sx-sdb: Add MQS support") originally set
pinctrl-0 = <>; in imx6sx-sdb-mqs.dts to override pinctrl-0 = <&pinctrl_sai1>;
from imx6sx-sdb.dtsi while leaving &audmux enabled.

When pinctrl-0 = <>; is simply removed, &sai1 retains pinctrl-0 = <&pinctrl_sai1>;
from imx6sx-sdb.dtsi while both &audmux and &sai1 have status = "okay",
causing pinctrl_bind_pins() -> pin_request() to fail with -EINVAL when the
second device probes.

Should this use /delete-property/ pinctrl-0; (and /delete-property/
pinctrl-names;) instead so that the inherited pinctrl properties are removed
from &sai1?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261016-arm_dts_cleanup2-v1-0-3a0cab9fd784@nxp.com?part=14