Re: [PATCH v7 2/7] arm64: dts: imx8mm: imx8mp: Add LVDS DTOs for Data Modul i.MX8M Mini and Plus eDM SBC

On Wed, Jul 29, 2026 at 10:06:34PM +0000, [email protected] wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
> - [Medium] Incorrect backlight enable GPIO and pinctrl applied for the g215hvn011 panel on the native i.MX8MP LVDS interface.
> - [Medium] The `assigned-clock-rates` property in `&media_blk_ctrl` lacks the required `assigned-clocks` property, causing the LVDS panel clock configuration to be silently ignored.
> --
>
> --- Patch [2]: [PATCH v7 2/7] arm64: dts: imx8mm: imx8mp: Add LVDS DTOs for Data Modul i.MX8M Mini and Plus eDM SBC ---
> commit 57ce2b382e55c1c98951209e8e0a8f4ea3f2c65c
> Author: Marek Vasut <[email protected]>
>
> arm64: dts: imx8mm: imx8mp: Add LVDS DTOs for Data Modul i.MX8M Mini and Plus eDM SBC
>
> This patch adds DT overlays for the DSI-to-LVDS adapter populated with a
> Lontium LT9211 bridge on Data Modul i.MX8M Mini and Plus eDM SBCs. It
> supports multiple panels for both the bridge and native i.MX8MP LVDS
> interfaces.
>
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-data-modul-edm-sbc-overlay-lvds-g215hvn011.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-data-modul-edm-sbc-overlay-lvds-g215hvn011.dtsi
> > new file mode 100644
> > index 0000000000000..3585170bd59dd
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/freescale/imx8mm-data-modul-edm-sbc-overlay-lvds-g215hvn011.dtsi
> > @@ -0,0 +1,30 @@
> [ ... ]
> > +&backlight {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_panel_backlight>;
> > +	enable-gpios = <&gpio3 0 GPIO_ACTIVE_HIGH>;
> > +	/* 6.5 POWER ON/OFF SEQUENCE, T6 >= 10 ms */
>
> [ ... ]
>
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc-overlay-edm-sbc-imx8mp-lvds-g215hvn011.dtso b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc-overlay-edm-sbc-imx8mp-lvds-g215hvn011.dtso
> > new file mode 100644
> > index 0000000000000..a6d13c3609796
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc-overlay-edm-sbc-imx8mp-lvds-g215hvn011.dtso
> > @@ -0,0 +1,36 @@
> [ ... ]
> > +&backlight {
> > +	power-supply = <&reg_panel_bl_supply>;
> > +};
>
> [Severity: Medium]
> Will this result in the wrong GPIO being toggled for the native i.MX8MP LVDS
> interface?
>
> The shared imx8mm-data-modul-edm-sbc-overlay-lvds-g215hvn011.dtsi file hardcodes
> enable-gpios to &gpio3 0 and defines a pinctrl. However, the native i.MX8MP
> LVDS interface uses the IO expander's &gpiowifi 0 (via reg_panel_bl in
> edm-sbc-imx8mp-lvds.dtsi).
>
> Since this overlay only overrides power-supply and does not remove the
> inapplicable pinctrl or override enable-gpios, won't the backlight driver
> toggle the incorrect baseboard adapter GPIO pin instead of the intended one?

I am not sure what's bad impact to wrong toggle enable-gpios. need check
this,

change exist ones to keep consistenet, all use enable-gpios or power-supply.


>
> [ ... ]
>
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc-overlay-edm-sbc-imx8mp-lvds-g101ice-l01.dtso b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc-overlay-edm-sbc-imx8mp-lvds-g101ice-l01.dtso
> > new file mode 100644
> > index 0000000000000..817d4ec62d0e8
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/freescale/imx8mp-data-modul-edm-sbc-overlay-edm-sbc-imx8mp-lvds-g101ice-l01.dtso
> > @@ -0,0 +1,24 @@
> [ ... ]
> > +&media_blk_ctrl {
> > +	/*
> > +	 * The G101ICE-L01 panel requires 71.1 MHz LVDS clock.
> > +	 * Set IMX8MP_VIDEO_PLL1 to 497.7 MHz , since 497.7 MHz / 7 = 71.1 MHz .
> > +	 */
> > +	assigned-clock-rates = <500000000>, <200000000>,
> > +			       <0>, <0>, <500000000>, <497700000>;
> > +};
>
> [Severity: Medium]
> Will this clock configuration be silently ignored by the clock framework?
>
> This overlay (and several others for the native LVDS interface) defines
> assigned-clock-rates without providing or inheriting an accompanying
> assigned-clocks array.
>
> The base board file imx8mp-data-modul-edm-sbc.dts does not include
> imx8mp-nominal.dtsi, where the assigned-clocks array is typically defined.
>
> When assigned-clocks is missing, of_parse_phandle_with_args() returns -ENOENT,
> and __set_clk_rates() silently skips setting the rates. Should assigned-clocks
> be explicitly defined here so the panel clock frequency is correctly set

This is most like false alarm. But for better read purpose, suggest
write whole group property

assign-clocks
assign-clock-parents
assign-clock-rates

Incase some change order in soc dtsi and forget update here and cause
wrong.

I met similar issue before.

the similar case is clocks and clock-names, should appear in pair at
every where.

Frank

>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=2