Re: [PATCH v6 5/5] arm64: dts: imx8mq-librem5: Correct link frequency list

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Critical] DT ABI Breakage: Removing existing link frequencies from the DT breaks backwards compatibility with older kernel drivers.
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commit e1f0f3ee9bb107c23572fda8db68e68a5ce30d59
Author: Pengyu Luo <mitltlatltl@gmail.com>

arm64: dts: imx8mq-librem5: Correct link frequency list

This commit corrects the link frequency list for the hi846 camera in the
imx8mq-librem5 device tree to match calculations from the datasheet.

> diff --git a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi b/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
> index f5d529c5baf3e..cc5604172192c 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi
> @@ -1122,7 +1122,7 @@ port {
>  			camera1_ep: endpoint {
>  				data-lanes = <1 2>;
>  				link-frequencies = /bits/ 64
> -					<80000000 200000000 300000000>;
> +					<187500000 375000000>;

[Severity: Critical]
Does removing the existing link frequencies here break backwards compatibility
with older kernels?

When an older kernel boots with this updated device tree, the hi846 driver
invokes hi846_parse_dt() and hi846_check_link_freqs(), which iterates through
its array of expected hardcoded frequencies (80000000 and 200000000) and
ensures each one is present in the DT.

Because this removes those legacy frequencies entirely instead of appending to
them, it appears the loop will fail to find a match and return -EINVAL, causing
the camera initialization to fail on older kernels (DT ABI breakage).

>  				remote-endpoint = <&mipi1_sensor_ep>;
>  			};
>  		};

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Sashiko AI review · https://sashiko.dev/#/patchset/20260830160025.211384-1-mitltlatltl@gmail.com?part=5