Re: [RFC PATCH 01/11] dt-bindings: media: qcom,sm8550-iris: Add vpu sub nodes

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

On 7/24/2026 4:45 PM, Dmitry Baryshkov wrote:
> On Thu, Jul 09, 2026 at 06:05:47PM +0530, Vikash Garodia wrote:
>> VPU hardwares have a limitation where VPU streams are associated with
>> dedicated addressable address range, as illustrated below
>>
>>      +-----------------------------------------------------------+
>>      | Stream A reserved region (600 MB)                         |
>>      | 0x00000000 - 0x25800000                                   |
>>      +-----------------------------------------------------------+
>>      | Stream B reserved region (3.5 GB)                         |
>>      | 0x00000000 - 0xe0000000                                   |
>>      +-----------------------------------------------------------+
>>      | Other reserved regions                                    |
>>      +-----------------------------------------------------------+
>>
>> Mapping a stream outside its expected range can cause unintended
>> behavior, including device crashes, as reported at:
>> https://gitlab.freedesktop.org/drm/msm/-/work_items/100
>>
>> To address this limitation, the subset of stream/s are now represented as
>> sub nodes, so that they can be associated to the respective addressable
>> range.
>> The limitation could be exposed when running usecase like concurrent
>> video sessions. The binding have been validated with higher concurrent
>> sessions across the SOCs supported under this schema.
>>
>> Co-developed-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
>> Signed-off-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
>> Signed-off-by: Vikash Garodia <vikash.garodia@oss.qualcomm.com>
>> ---
>>   .../bindings/media/qcom,sm8550-iris.yaml           | 66 +++++++++++++++++++++-
>>   1 file changed, 63 insertions(+), 3 deletions(-)
>>
>> +
>> +  firmware:
> 
> Venus devices have been using 'video-firmware' here. Can we please use
> that name? Or I'd ask differently: what is the reason for deviating from
> the name that has already been used?
> 

fair point. The primary reason was to keep it aligned with other 
subnodes (pixel/non-pixel) which does not have the video prefix. For 
firmware, it would be more appropriate to keep it same as defined 
earlier "video-firmware"

>> +    type: object
>> +    description:
>> +      Firmware context bank represents the firmware processing domain of the VPU. Required to boot
>> +      VPU when no hypervisor is present.
>> +    properties:
>> +      iommus:
>> +        maxItems: 1
>> +    required:
>> +      - iommus
>> +    additionalProperties: false
>> +
>