Re: [PATCH v2 2/3] arm64: dts: qcom: Add HP EliteBook X G2q 14 AI

[Dmitry Baryshkov]

On Sat, Jun 27, 2026 at 12:06:12PM -0700, Jason Pettit wrote:
> On Fri, 26 Jun 2026 13:27:42 +0200, Konrad Dybcio wrote:
> > If you remove these two nodes, the QMPPHY-as-DP-only should still
> > function (it's the USB3 block that depends on the QMPPHY, not the
> > other way around)
> 
> Apologies for the duplicate. My earlier copy of this reply went out with a
> misconfigured sender identity from a local mail setup issue. Resending it
> cleanly.
> 
> I boot-tested this. With &usb_2 and &usb_2_hsphy removed, dmesg still
> shows the af64000 DP controller binding and /sys/class/drm shows the
> HDMI-A-1 connector as connected, but nothing is displayed on the attached
> monitor. With both nodes present, the monitor shows an image.
> 
> So removing them stops HDMI from working on this board.
> The comment in v3 will be updated to read:
> 
> 	/* usb_2's combo PHY drives the HDMI bridge over DP; keep the dwc3 enabled. */

This is very surprising. Can you check, is it actually the DWC3 or is it
some power supply that is being toggled by the USB controller? In the
former case it would mean that we miss some bits of PHY programming and
still depend on the USB host / USB part of the PHY.


-- 
With best wishes
Dmitry