Re: [PATCH 1/1] ARM: dts: imx6sx: remove fallback compatible string fsl,imx28-lcdif

[Liu Ying]

On Thu, Mar 05, 2026 at 04:23:11PM -0500, Frank Li wrote:
> i.MX6SX uses the v6 LCDIF controller, while i.MX28 uses the older v4

V6 is a Linux thing as mxsfb_drv.c says:
/*
 * Starting at i.MX6 the hardware version register is gone, use the
 * i.MX family number as the version.
 */
MXSFB_V6,

I think it would be good to make the commit mesg independent from Linux.
You may say something like "i.MX6SX LCDIF is not compatible with
i.MX28 LCDIF from HW IP point of view like missing a/b/c registers".

> version. The driver has supported the "fsl,imx6sx-lcdif" compatible string
> since the initial commit:
> 
>    commit 45d59d704080 ("drm: Add new driver for MXSFB controller")
> 
> Therefore the fallback compatible string "fsl,imx28-lcdif" is not required
> and can be removed.
> 
> Fix the following CHECK_DTB warning:
> /arch/arm/boot/dts/nxp/imx/imx6sx-nitrogen6sx.dtb: lcdif@2220000 (fsl,imx6sx-lcdif): compatible: 'oneOf' conditional failed, one must be fixed:
>         ['fsl,imx6sx-lcdif', 'fsl,imx28-lcdif'] is too long
> 
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>

Since this is a fix, worth a Fixes tag?

> ---
> Cc: Liu Ying <victor.liu@xxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> Previous Fabio Estevam work try to allow fallback at
> https://lore.kernel.org/imx/42eb2d42-47b0-46b6-92e9-c59473113c2d@xxxxxxx/
> ---
>  arch/arm/boot/dts/nxp/imx/imx6sx.dtsi | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/nxp/imx/imx6sx.dtsi b/arch/arm/boot/dts/nxp/imx/imx6sx.dtsi
> index 1426f357d4744..aefae5a3a6beb 100644
> --- a/arch/arm/boot/dts/nxp/imx/imx6sx.dtsi
> +++ b/arch/arm/boot/dts/nxp/imx/imx6sx.dtsi
> @@ -1304,7 +1304,7 @@ csi2: csi@221c000 {
>  				};
>  
>  				lcdif1: lcdif@2220000 {
> -					compatible = "fsl,imx6sx-lcdif", "fsl,imx28-lcdif";
> +					compatible = "fsl,imx6sx-lcdif";
>  					reg = <0x02220000 0x4000>;
>  					interrupts = <GIC_SPI 5 IRQ_TYPE_EDGE_RISING>;
>  					clocks = <&clks IMX6SX_CLK_LCDIF1_PIX>,
> @@ -1325,7 +1325,7 @@ lcdif1_to_ldb: endpoint {
>  				};
>  
>  				lcdif2: lcdif@2224000 {
> -					compatible = "fsl,imx6sx-lcdif", "fsl,imx28-lcdif";
> +					compatible = "fsl,imx6sx-lcdif";
>  					reg = <0x02224000 0x4000>;
>  					interrupts = <GIC_SPI 6 IRQ_TYPE_EDGE_RISING>;
>  					clocks = <&clks IMX6SX_CLK_LCDIF2_PIX>,

-- 
Regards,
Liu Ying