linux-kernel - Re: [PATCH v5 1/3] arm64: dts: qcom: x1e80100: add epd hpd pinctrl

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Message-ID: <aICP5pE6oXFIxHVk@hovoldconsulting.com>
Date: Wed, 23 Jul 2025 09:31:50 +0200
From: Johan Hovold <johan@...nel.org>
To: Neil Armstrong <neil.armstrong@...aro.org>
Cc: Christopher Obbard <christopher.obbard@...aro.org>,
	Douglas Anderson <dianders@...omium.org>,
	Jessica Zhang <quic_jesszhan@...cinc.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Bjorn Andersson <andersson@...nel.org>,
	Konrad Dybcio <konradybcio@...nel.org>,
	Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>,
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
	linux-arm-msm@...r.kernel.org,
	Rui Miguel Silva <rui.silva@...aro.org>,
	Abel Vesa <abel.vesa@...aro.org>, devicetree@...r.kernel.org
Subject: Re: [PATCH v5 1/3] arm64: dts: qcom: x1e80100: add epd hpd pinctrl

On Wed, Jul 23, 2025 at 09:03:40AM +0200, Neil Armstrong wrote:
> On 11/04/2025 13:49, Johan Hovold wrote:
> > On Wed, Apr 02, 2025 at 03:36:32PM +0100, Christopher Obbard wrote:
> >> Add edp_hpd_active pinctrl to the X1E80100 device tree.
> > 
> > Please squash this one with the patch adding the user.
> >   
> >> Signed-off-by: Christopher Obbard <christopher.obbard@...aro.org>
> >> ---
> >>   arch/arm64/boot/dts/qcom/x1e80100.dtsi | 5 +++++
> >>   1 file changed, 5 insertions(+)
> >>
> >> diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> >> index 46b79fce92c90d969e3de48bc88e27915d1592bb..5b1b80c445404fd02e9f6e5dab207610b03ff9c5 100644
> >> --- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> >> +++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
> >> @@ -6389,6 +6389,11 @@ data-pins {
> >>   					bias-pull-up;
> >>   				};
> >>   			};
> >> +
> >> +			edp_hpd_active: edp-hpd-active-state {
> > 
> > Please keep the nodes sorted by name.
> > 
> >> +				pins = "gpio119";
> >> +				function = "edp_hot";
> > 
> > There is no "edp_hot" function on x1e so I wonder how this has been
> > tested.
> > 
> > As I mentioned in a comment to an earlier revision this pin has been
> > configured by the firmware as "edp0_hot".
> 
> With edp_hot, screen stays black with UI comes up, with edp0_hot it works again.

Right.

> > Since there is also an "edp1_hot" pin, this needs to be reflected in the
> > node name and label.
> > 
> > Pin configurations really do belong in board files, but unfortunately
> > this was not followed for x1e. You should still include the bias
> > configuration (somewhere).
> 
> Which bias ? do this pin config needs an additional bias config ?

The boot firmware has disabled the bias, but we should not rely on the
firmware to have configured the pin for us.

Johan