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

[Stephan Gerhold]

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.
> 
> 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>

IMHO (the DT maintainers might disagree) this is not a different
BAM DMUX hardware block on Shikra, just a different firmware
configuration. I'm sure the existing SoCs also have those XPU blocks,
they just don't make use of it.

Personally, I would rather describe this with an optional "qcom,vmid"
property similar to your bam-dma patch, allowed for all SoCs.

Thanks,
Stephan