Re: [PATCH 3/5] arm64: dts: qcom: milos: Add WCN6750 WiFi node

[Luca Weiss]

Hi Konrad,

On Tue Jan 20, 2026 at 3:39 PM CET, Konrad Dybcio wrote:
> On 1/16/26 3:50 PM, Luca Weiss wrote:
>> Add a node for the WCN6750 WiFi found with the Milos SoC.
>> 
>> Signed-off-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
>> ---
>>  arch/arm64/boot/dts/qcom/milos.dtsi | 46 +++++++++++++++++++++++++++++++++++++
>>  1 file changed, 46 insertions(+)
>> 
>> diff --git a/arch/arm64/boot/dts/qcom/milos.dtsi b/arch/arm64/boot/dts/qcom/milos.dtsi
>> index 024e1c9992fe..80feb3e9d3e2 100644
>> --- a/arch/arm64/boot/dts/qcom/milos.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/milos.dtsi
>> @@ -2043,6 +2043,52 @@ gic_its: msi-controller@17140000 {
>>  			};
>>  		};
>>  
>> +		wifi: wifi@17110040 {
>> +			compatible = "qcom,wcn6750-wifi";
>> +			reg = <0x0 0x17110040 0x0 0x0>;
>
> This reg doesn't.. sound.. very.. good..
>
> The size being 0 is of course wrong, but perhaps more interestingly
> the base address is a register within the GIC..
>
>> +			iommus = <&apps_smmu 0x1400 0x1>;
>
> And this is a PCIe stream
>
> But I see kodiak has the exact same setup..
>
> After digging a little into the driver, that 'reg' is apparently
> indeed consumed, as a base for PCI MSIs.. I feel like there should be
> some better way to express this.. non-everyday setup
>
> There's this commit message:
>
> commit 00fd24089b8154ddf5b3e724e2c4c9974b9ba91e
> Author: Manikanta Pubbisetty <quic_mpubbise@xxxxxxxxxxx>
> Date:   Fri Apr 29 22:34:54 2022 +0530
>
>     dt: bindings: net: add bindings of WCN6750 for ath11k
>     
>     WCN6750 is the WLAN chip on Qualcomm Snapdragon SoC SC7280;
>     Though being a PCIe based solution, it is not attached to
>     the APSS processor (Application Processor SubSystem), it is
>     instead attached to another tiny processor called WPSS Q6
>     processor (Wireless Processor SubSystem) on the SC7280 MSM,
>     where the WLAN firmware runs, and it is the WLAN firmware
>     running on the Q6 processor which enumerates WCN6750, as a
>     result APPS processor would never know such a device being
>     present in the system and would not detect the WCN6750
>     hardware unless and otherwise WCN6750 is registered as a
>     platform device. This is the reason behind adding WCN6750
>     WLAN node in the device tree.
>     
>     Add WCN6750 wireless driver support, its based on ath11k driver.
>
> Sorry to hijack this patch, but I am not comfortable with this binding
> as-is..
>
> Adding +Jeff in case he has any thoughts

To be honest I find it a bit discouraging to get this relatively simple
patch with existing bindings blocked. Yes, the bindings are probably bad
(not that I can really judge) but sc7280/kodiak already uses them and
it's functional, so I don't know what I would need to change.

Re-designing the bindings and driver seems a bit overkill to get milos
wifi upstream.

Regards
Luca