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

[Vishnu Santhosh <vishnu.santhosh@oss.qualcomm.com>]

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@oss.qualcomm.com
>> prerequisite-patch-id: c3d19e8dbf9451f9f8155c86c21a4e6b5dc796d0
>> prerequisite-message-id: 20260920-qcom-bam-dma-vmid-ext-v2-1-4dbbff0e57c8@oss.qualcomm.com
>> prerequisite-patch-id: 30840b157a197cc896556c0152b26a00abba0010
>> prerequisite-message-id: 20260920-qcom-bam-dmux-vmid-ext-v2-0-ef5ca2178378@oss.qualcomm.com
>> 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