Re: [PATCH v2 0/3] arm64: dts: qcom: kodiak: Enable 4-lane DP via QMP Combo PHY

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 5/22/26 5:41 AM, Bjorn Andersson wrote:
> On Wed, Apr 29, 2026 at 12:10:39PM +0530, Mahadevan P wrote:
>> This series enables full 4-lane DisplayPort operation on SC7280/kodiak
>> platforms by wiring up the QMP Combo PHY correctly and consolidating
>> the DP endpoint configuration in the SoC dtsi.
>>
>> Patch 1 adds mode-switch to the QMP Combo PHY node in kodiak.dtsi,
>> which is required for the PHY to respond to USB-C Alternate Mode
>> negotiation and switch into 4-lane DP configuration.
>>
>> Patch 2 moves the data-lanes property from individual board files into
>> kodiak.dtsi since the PHY-to-controller wiring is fixed in silicon.
>> It also removes redundant remote-endpoint and orientation-switch
>> overrides from qcs6490-rb3gen2 and qcs6490-thundercomm-rubikpi3 that
>> are already covered by the SoC dtsi.
>>
>> Patch 3 updates data-lanes from <0 1> to <0 1 2 3> in kodiak.dtsi now
>> that mode-switch is in place, enabling the full 4-lane DP link.
> 
> Are you sure that herobrine has 4 lanes routed on the PCB?

+Doug any chance you still have schematics for that old boy?

Bjorn, perhaps we could switch to a model where we define the max
capabilities (i.e. 4-lane 8.1 GHz link) in the SoC DTs and only limit
them as necessary? Not meeting these is borderline a board defect anyway

Konrad