Re: [PATCH RFC 0/2] arm64: dts: qcom: eliza: Add display

[Krzysztof Kozlowski <krzk@kernel.org>]

On 31/03/2026 17:03, Konrad Dybcio wrote:
> On 3/31/26 5:01 PM, Krzysztof Kozlowski wrote:
>> On 31/03/2026 16:49, Konrad Dybcio wrote:
>>> On 3/31/26 4:02 PM, Krzysztof Kozlowski wrote:
>>>> Dependency
>>>> ==========
>>>> Depends on USB patches, which are being reviewed, therefore marking it
>>>> as RFC as it cannot be applied.
>>>> https://lore.kernel.org/all/20260331-eliza-adsp-usb-v1-0-d8a251be20c3@oss.qualcomm.com/
>>>>
>>>> Unmerged bindings used here
>>>> ===========================
>>>> dispcc: https://lore.kernel.org/all/20260319-clk-qcom-dispcc-eliza-v3-0-d1f2b19a6e6b@oss.qualcomm.com/
>>>> (DRM MDSS bindings were applied)
>>>>
>>>> Description
>>>> ===========
>>>> I did not enable DisplayPort because it does not work on my board and I
>>>> don't know why. I double checked QMP combo phy and other bits, and
>>>> everything is looking fine, but still no USB display, so maybe I miss
>>>> some other dependencies as this is early upstream.
>>>
>>> What was the furthest that you got? We can certainly try to help..
>>>
>>> Got USB Type-C mode mux events?
>>> PHY initialized and configured to 2/4-lane DP mode?
>>> Are the AUX transfers failling?
>>
>> [   43.975329] msm_dpu ae01000.display-controller: [drm:drm_dp_dpcd_access] dpu_dp_aux: Too many retries, giving up. First error: -110
>> [   43.975410] msm_dpu ae01000.display-controller: [drm:drm_dp_dpcd_probe] dpu_dp_aux: 0x00102 AUX -> (ret=-110)
>> [   45.780383] msm_dpu ae01000.display-controller: [drm:drm_dp_dpcd_access] dpu_dp_aux: Too many retries, giving up. First error: -110
>> [   45.780463] msm_dpu ae01000.display-controller: [drm:drm_dp_dpcd_probe] dpu_dp_aux: 0x00102 AUX -> (ret=-110)
>> [   45.780521] msm_dpu ae01000.display-controller: [drm:msm_dp_pm_runtime_suspend] type=10 core_init=1 phy_init=1
>>
>> pastebin: https://pastebin.com/BVXy3Qeq
>>
>> Abel pointed me to the phy problems, so I focused on that.
>> HSR says it is exactly same programming sequence as SM8650
>> and such was used.
>>
>> Just note, that we have ADSP remoteproc up, but no audio including USB mux,
> 
> Are you talking about wcd939x-mux?

Yes

> 
> If so, you need that or the lanes won't be properly connected

Ha! That would explain, although I had impression that with disabled
WCD939x mux the SM8750 DP still works.

Well, I don't have that WCD939x and it is left for other team to finish
a bit later, so we can leave the USB DP for now. I will re-visit that
when audio progresses.

Best regards,
Krzysztof