Re: [PATCH v2 01/23] dt-bindings: display: msm: Add Qualcomm DCP

[Jayant Shekhar <jayant.shekhar@oss.qualcomm.com>]

On 27-10-2026 01:14, Rob Herring (Arm) wrote:
> On Mon, 26 Oct 2026 11:51:11 +0530, Jayant Shekhar wrote:
>> DCP platforms place the display pipeline under firmware control, so Linux
>> cannot discover display resources through direct register access. The DRM
>> driver therefore needs device-tree descriptions of the Qualcomm transport
>> wrapper, display topology, IOMMU contexts, and panel connections.
>>
>> Add bindings for the Qualcomm DCP transport wrapper and VirtIO display
>> subsystem. Document the IPCC power-notify resources, transport and
>> framebuffer IOMMU contexts, firmware-visible IOVA range, INTF graph, and
>> DSI panel connections. The wrapper creates a standard VirtIO-MMIO child
>> after the IPCC power-notify sequence has completed.
>>
>> Assisted-by: LLM
>> Signed-off-by: Jayant Shekhar <jayant.shekhar@oss.qualcomm.com>
>> ---
>>   .../bindings/display/msm/qcom,dcp-dsi.yaml         |  79 ++++++++++++
>>   .../devicetree/bindings/display/msm/qcom,dcp.yaml  | 123 +++++++++++++++++++
>>   .../bindings/virtio/qcom,dcp-virtio.yaml           | 132 +++++++++++++++++++++
>>   3 files changed, 334 insertions(+)
>>
> My bot found errors running 'make dt_binding_check' on your patch:
>
> yamllint warnings/errors:
>
> dtschema/dtc warnings/errors:
> /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/virtio/qcom,dcp-virtio.yaml: iommu-ranges: multiple incompatible types: uint32-array
> /usr/local/lib/python3.13/dist-packages/dtschema/schemas/iommu/iommu.yaml: iommu-ranges: multiple incompatible types: uint32-matrix
> Could not decode node virtio@9be8000 property iommu-ranges with value b'\x00\x00\x00\x00\x84\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00'
>
> Traceback (most recent call last):
>    File "/usr/local/bin/dt-validate", line 8, in <module>
>      sys.exit(main())
>               ~~~~^^
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb_validate.py", line 443, in main
>      dtb_diagnostics = sg.check_dtb(filename)
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb_validate.py", line 331, in check_dtb
>      dt = self.validator.decode_dtb(f.read(), decode_errors)
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/validator.py", line 631, in decode_dtb
>      return [dtschema.dtb.fdt_unflatten(self, dtb)]
>              ~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb.py", line 591, in fdt_unflatten
>      dt = fdt_scan_node(validator, fdt, '/', offset)
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb.py", line 320, in fdt_scan_node
>      node = fdt_scan_node(validator, fdt, nodename, offset)
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb.py", line 320, in fdt_scan_node
>      node = fdt_scan_node(validator, fdt, nodename, offset)
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb.py", line 312, in fdt_scan_node
>      node_dict = node_props(validator, fdt, nodename, offset)
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb.py", line 258, in node_props
>      props_dict[p.name] = prop_value(validator, nodename, p)
>                           ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
>    File "/usr/local/lib/python3.13/dist-packages/dtschema/dtb.py", line 185, in prop_value
>      if len(p) / type_format[fmt].size >= min_dim:
>                  ~~~~~~~~~~~^^^^^
> KeyError: 'uint32-array'
>
> doc reference errors (make refcheckdocs):
>
> See https://patchwork.kernel.org/project/devicetree/patch/20261026-jshekhar-dcp-hlos-v2-1-7cf014efdee1@oss.qualcomm.com
>
> The base for the series is generally the latest rc1. A different dependency
> should be noted in *this* patch.
>
> If you already ran 'make dt_binding_check' and didn't see the above
> error(s), then make sure 'yamllint' is installed and dt-schema is up to
> date:
>
> pip3 install dtschema --upgrade
>
> Please check and re-submit after running the above command yourself. Note
> that DT_SCHEMA_FILES can be set to your schema file to speed up checking
> your schema. However, it must be unset to test all examples with your schema.


There is a dependent patch which adds iommu-ranges, I had tried with 
that locally and it passes.