Re: [PATCH 1/2] dt-bindings: net: qcom,bam-dmux: Add qcom,shikra-bam-dmux compatible

[Vishnu Santhosh]

On 21-07-2026 02:47 pm, Krzysztof Kozlowski wrote:
> On Tue, Jul 14, 2026 at 11:02:31AM +0530, Vishnu Santhosh wrote:
> > On platforms where the modem DMAs into the BAM-DMUX RX data buffers and
> > the XPU enforces per-region access control, each individually
> > DMA-mapped RX buffer consumes an XPU resource group. With only ~16
> > groups available, the per-buffer mappings exhaust the table and inbound
> > transfers fault.
> >
> > Add qcom,shikra-bam-dmux as an additional compatible for the Shikra SoC,
> > paired with the generic qcom,bam-dmux fallback, so the driver can match
> > on it via its of_device_id table.
> Drop, redundant. What is not redundant, why you claim it is compatible
> but driver code suggests it is not incompatible.

Agreed. I will drop the compatible change.

> > Co-developed-by: Deepak Kumar Singh <deepak.singh@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Deepak Kumar Singh <deepak.singh@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Vishnu Santhosh <vishnu.santhosh@xxxxxxxxxxxxxxxx>
> > ---
> >   Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml | 8 +++++++-
> >   1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml b/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml
> > index 33746c238513d72366bc52359fb10f275475b331..27f0fdf285c17d6bfdecd5e59cad09912a5e821b 100644
> > --- a/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml
> > +++ b/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml
> > @@ -22,7 +22,13 @@ description: |
> >   
> >   properties:
> >     compatible:
> > -    const: qcom,bam-dmux
> > +    oneOf:
> > +      - const: qcom,bam-dmux
> > +      - items:
> > +          - enum:
> > +              # Shikra
> Please do not write redundant code or commit msgs. Look:

Agreed.

> > +              - qcom,shikra-bam-dmux
> It has word "shikra". Can qcom,shikra-bam-dmux be anything else than
> "Shikra"? Then why adding such comment?

Got the point. I will drop the comment along with the compatible.

> > +          - const: qcom,bam-dmux
> Anyway, the generic compatible was added to cover all possible use
> cases, right? So why it is not generic enough here? One more example of
> generic compatibles failure.
>
> Best regards,
> Krzysztof

Thanks for pointing this out. I'll send the v2 with a qcom,vmid(s) property
like we have in multiple other bindings (rmtfs, fastrpc, ...), instead of this
new compatible, so that it can be used for handling specific firmware security
configurations in Shikra.

Vishnu

>