Re: [PATCH v3] arm64: dts: qcom: shikra: Add BAM-DMUX support

[Vishnu Santhosh]

On 15-10-2026 02:52 pm, Konrad Dybcio wrote:
> On 9/20/26 5:28 AM, Vishnu Santhosh wrote:
> > Add the SMSM state entries, BAM-DMUX node, and BAM DMA controller needed
> > to provide modem data channels on Shikra.
> >
> > Reserve a 256 KiB restricted DMA pool and reference it from both the
> > BAM-DMUX and BAM DMA nodes. Set qcom,vmid to NAV so the BAM-DMUX driver
> > can grant the modem access to the complete pool before requesting the DMA
> > channels.
> [...]
>
> > +	smsm {
> > +		compatible = "qcom,smsm";
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +		mboxes = <0>, <&apcs_glb 13>;
> Why is there a "null" reference?

Each mboxes entry is the outgoing doorbell for the SMSM host with the
same index. Index 0 is the apps processor itself (apps@0), which has no
doorbell, so <0> keeps the modem doorbell at index 1. msm8916.dtsi uses
the same layout.

> > +		apps_smsm: apps@0 {
> > +			reg = <0>;
> > +			#qcom,smem-state-cells = <1>;
> > +		};
> > +		modem_smsm: modem@1 {
> > +			reg = <1>;
> > +			interrupts = <GIC_SPI 69 IRQ_TYPE_EDGE_RISING 0>;
> > +			interrupt-controller;
> > +			#interrupt-cells = <2>;
> > +		};
> Please retain a newline between each subnode and between the last property
> and the first subnode

ok. I will fix in next revision.

> > +	};
> > +
> >   	soc: soc@0 {
> >   		compatible = "simple-bus";
> >   
> > @@ -1866,6 +1891,20 @@ glink-edge {
> >   				qcom,remote-pid = <1>;
> >   				label = "mpss";
> >   			};
> > +
> > +			bam_dmux: bam-dmux {
> Nodes should be sorted within their scope

ok. I will fix in next revision.

> > +				compatible = "qcom,bam-dmux";
> > +				interrupt-parent = <&modem_smsm>;
> > +				interrupts = <1 IRQ_TYPE_EDGE_BOTH>,
> > +					     <11 IRQ_TYPE_EDGE_BOTH>;
> interrupts-extended = <&foo bar baz>

ok. I will fix in next revision.

> > +				interrupt-names = "pc", "pc-ack";
> > +				qcom,smem-states = <&apps_smsm 1>, <&apps_smsm 11>;
> > +				qcom,smem-state-names = "pc", "pc-ack";
> 1 entry a line, please
>
> [...]

ok. I will fix in next revision.

> > base-commit: 518e5b794c06c0f0eb40df3e202274a66202c137
> > change-id: 20260603-qcom-shikra-dts-bam-dmux-7fdcbb6fb662
> > prerequisite-message-id: 20260908-shikra-pas-bam-dmux-binding-v4-1-6044889e7e3d@xxxxxxxxxxxxxxxx
> > prerequisite-patch-id: c3d19e8dbf9451f9f8155c86c21a4e6b5dc796d0
> > prerequisite-message-id: 20260920-qcom-bam-dma-vmid-ext-v2-1-4dbbff0e57c8@xxxxxxxxxxxxxxxx
> > prerequisite-patch-id: 30840b157a197cc896556c0152b26a00abba0010
> > prerequisite-message-id: 20260920-qcom-bam-dmux-vmid-ext-v2-0-ef5ca2178378@xxxxxxxxxxxxxxxx
> > prerequisite-patch-id: a9c2ce26fabf293f94f384409991f8a9b3afaafa
> > prerequisite-patch-id: c4d2876bea87e825468eb3bd116bfdf5a203f7c1
> This list screams ""can't merge this patch"". Please either send changes
> in a series or hold off until the dependencies are met.
>
> Konrad

Understood.

Vishnu