Re: [PATCH v4 1/3] dt-bindings: media: qcom,qcm2290-venus: document shikra Iris compatible

[Vikash Garodia <vikash.garodia@oss.qualcomm.com>]

On 7/22/2026 12:45 PM, Krzysztof Kozlowski wrote:
> On Tue, Jul 21, 2026 at 11:02:25PM +0530, Vikash Garodia wrote:
>> Document the iris video accelerator used on shikra platforms by adding
>> the qcom,shikra-iris compatible.
> 
> iris here, venus in the compatible. Please decide which one.

Ack. Should fix the commit here to mention it as qcom,shikra-venus.

> 
>>
>> Although QCM2290 and shikra share the same video hardware and overall
>> integration, their SMMU programming differs. QCM2290 exposes separate
>> stream IDs for the video hardware and the Xtensa path, requiring two
>> explicit IOMMU entries, whereas shikra uses a masked SMR to collapse
>> equivalent stream IDs into a single mapping. Due to QCM2290’s SID layout
>> and Xtensa isolation requirements, such SMR masking is not applicable on
>> QCM2290 platforms.
> 
> This paragraph suggests devices are not compatible. Will Shikra Iris
> work fine when driver matches with qcom,qcm2290-venus?
> 

Validated shikra with qcom,shikra-venus as fallback compatible to 
qcom,qcm2290-venus.

>> Since shikra uses the same video hardware as QCM2290 and shares the same
>> programming model and capabilities, it is added as a fallback compatible
>> to qcom,qcm2290-venus, with conditional handling to allow either one or
>> two IOMMU entries.
>> Common schema is updated to accommodate the iova restriction of 600MB.
>> VPU restricts usage of 600MB for specific streams, which could otherwise
>> lead to device crash.
>>
>> Reviewed-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
>> Signed-off-by: Vikash Garodia <vikash.garodia@oss.qualcomm.com>
>> ---
>>   .../bindings/media/qcom,qcm2290-venus.yaml         | 26 ++++++++++++++++------
>>   .../bindings/media/qcom,venus-common.yaml          |  5 ++++-
>>   2 files changed, 23 insertions(+), 8 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/media/qcom,qcm2290-venus.yaml b/Documentation/devicetree/bindings/media/qcom,qcm2290-venus.yaml
>> index 5977e7d0a71b4fb5681f1c2094439c251366f01f..b27899ebf164229ceff1ca5cda50ee30d875e953 100644
>> --- a/Documentation/devicetree/bindings/media/qcom,qcm2290-venus.yaml
>> +++ b/Documentation/devicetree/bindings/media/qcom,qcm2290-venus.yaml
>> @@ -13,14 +13,13 @@ description:
>>     The Venus AR50_LITE IP is a video encode and decode accelerator present
>>     on Qualcomm platforms.
>>   
>> -allOf:
>> -  - $ref: qcom,venus-common.yaml#
>> -
>>   properties:
>>     compatible:
>>       oneOf:
>>         - items:
>> -          - const: qcom,sm6115-venus
>> +          - enum:
>> +              - qcom,shikra-venus
>> +              - qcom,sm6115-venus
>>             - const: qcom,qcm2290-venus
>>         - const: qcom,qcm2290-venus
>>   
>> @@ -45,9 +44,6 @@ properties:
>>         - const: vcodec0_core
>>         - const: vcodec0_bus
>>   
>> -  iommus:
>> -    maxItems: 2
>> -
>>     interconnects:
>>       maxItems: 2
>>   
>> @@ -65,6 +61,22 @@ required:
>>     - power-domain-names
>>     - iommus
>>   
>> +allOf:
>> +  - $ref: qcom,venus-common.yaml#
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            const: qcom,shikra-venus
>> +    then:
>> +      properties:
>> +        iommus:
>> +          maxItems: 1
>> +    else:
>> +      properties:
>> +        iommus:
>> +          maxItems: 2
>> +
>>   unevaluatedProperties: false
>>   
>>   examples:
>> diff --git a/Documentation/devicetree/bindings/media/qcom,venus-common.yaml b/Documentation/devicetree/bindings/media/qcom,venus-common.yaml
>> index 59a3fde846d2196ab1e4588eb396012ba6860712..0be2f9119e78233928d23af86836ac294aa769ee 100644
>> --- a/Documentation/devicetree/bindings/media/qcom,venus-common.yaml
>> +++ b/Documentation/devicetree/bindings/media/qcom,venus-common.yaml
>> @@ -37,7 +37,10 @@ properties:
>>       maxItems: 20
>>   
>>     memory-region:
>> -    maxItems: 1
>> +    minItems: 1
>> +    items:
>> +      - description: Firmware-loaded codec carveout
>> +      - description: IOMMU IOVA reservation region
> 
> This adds second region to several other devices using
> qcom,venus-common.yaml, thus should be its own commit with its own
> rationale why all devices take the IOMMU IOVA region now.
> 

Sure, i can split the common yaml as a separate preceding commit with 
justification on need of separate IOVA region.

Regards,
Vikash

>>   
>>     power-domains:
>>       minItems: 1
>>
>> -- 
>> 2.34.1
>>