Re: [PATCH v7 04/23] dt-bindings: media: qcom,eliza-camss: Add Eliza CAMSS

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] dt-bindings: media: qcom,eliza-camss: invalid 0-based data-lanes
  in example
--

commit bce0133de93b87d5e9e002d47e94f2395d97b15f
Author: Wenmeng Liu <wenmeng.liu@oss.qualcomm.com>

dt-bindings: media: qcom,eliza-camss: Add Eliza CAMSS

This commit adds the Device Tree binding schema and example for the Camera
Subsystem (CAMSS) on the Qualcomm Eliza platform.

> diff --git a/Documentation/devicetree/bindings/media/qcom,eliza-camss.yaml b/Documentation/devicetree/bindings/media/qcom,eliza-camss.yaml
> new file mode 100644
> index 0000000000000..8775ec6a2f69b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/qcom,eliza-camss.yaml
> @@ -0,0 +1,282 @@
[ ... ]
> +        properties:
> +          endpoint:
> +            $ref: video-interfaces.yaml#
> +            unevaluatedProperties: false
> +
> +            properties:
> +              data-lanes:
> +                minItems: 1
> +                maxItems: 4
[ ... ]
> +            ports {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                port@0 {
> +                    reg = <0>;
> +
> +                    camss_csiphy0_ep: endpoint {
> +                        data-lanes = <0 1 2 3>;
> +                        remote-endpoint = <&csiphy0_out>;
> +                    };

[Severity: Low]
Should data-lanes in the example be 1-based (<1 2 3 4>) instead of 0-based
(<0 1 2 3>)?

Because Eliza uses standalone CSIPHY devices without legacy CSIPHY
resources, camss_detect_legacy_phy() sets camss->legacy_phy to false and
camss_parse_ports() sets lane_base to 1.  camss_parse_endpoint_node() then
rejects lane 0 with -EINVAL:

drivers/media/platform/qcom/camss/camss.c:camss_parse_endpoint_node() {
    ...
		if (lane < lane_base || lane - lane_base >= MSM_CSIPHY_MAX_DATA_LANE) {
			dev_err(dev, "invalid data-lane %u\n", lane);
			return -EINVAL;
		}
    ...
}

Any Device Tree modeled after this example will fail to probe.  The
endpoint data-lanes schema above also only constrains minItems and
maxItems, so adding items with minimum: 1 and maximum: 4 would allow
dtbs_check to catch 0-based lane indices.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261114-add-support-for-camss-on-sm8750-v7-0-8ff2a11835f6@oss.qualcomm.com?part=4