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

[Vikash Garodia]

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@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
> > ---
> >   .../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
> > +