Re: [PATCH RFT 0/7] arm64: qcom: allow up to 4 lanes for the Type-C DisplayPort Altmode

From: "Luca Weiss" <luca.weiss@fairphone.com>
To: "Neil Armstrong" <neil.armstrong@linaro.org>,
	"Bjorn Andersson" <andersson@kernel.org>,
	"Konrad Dybcio" <konrad.dybcio@linaro.org>,
	"Vinod Koul" <vkoul@kernel.org>,
	"Kishon Vijay Abraham I" <kishon@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>
Cc: <linux-arm-msm@vger.kernel.org>, <linux-phy@lists.infradead.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFT 0/7] arm64: qcom: allow up to 4 lanes for the Type-C DisplayPort Altmode
Date: Fri, 15 Mar 2024 18:19:47 +0100	[thread overview]
Message-ID: <CZUHV429NTF7.1GW9TN9NXB4J1@fairphone.com> (raw)
In-Reply-To: <20240229-topic-sm8x50-upstream-phy-combo-typec-mux-v1-0-07e24a231840@linaro.org>

On Thu Feb 29, 2024 at 2:07 PM CET, Neil Armstrong wrote:
> Register a typec mux in order to change the PHY mode on the Type-C
> mux events depending on the mode and the svid when in Altmode setup.
>
> The DisplayPort phy should be left enabled if is still powered on
> by the DRM DisplayPort controller, so bail out until the DisplayPort
> PHY is not powered off.
>
> The Type-C Mode/SVID only changes on plug/unplug, and USB SAFE states
> will be set in between of USB-Only, Combo and DisplayPort Only so
> this will leave enough time to the DRM DisplayPort controller to
> turn of the DisplayPort PHY.
>
> The patchset also includes bindings changes and DT changes.
>
> This has been successfully tested on an SM8550 board, but the
> Thinkpad X13s deserved testing between non-PD USB, non-PD DisplayPort,
> PD USB Hubs and PD Altmode Dongles to make sure the switch works
> as expected.
>
> The DisplayPort 4 lanes setup can be check with:
> $ cat /sys/kernel/debug/dri/ae01000.display-controller/DP-1/dp_debug
> 	name = msm_dp
> 	drm_dp_link
> 		rate = 540000
> 		num_lanes = 4

Hi Neil,

I tried this on QCM6490/SC7280 which should also support 4-lane DP but I
haven't had any success so far.

On top of your patches I added the following for my device:

diff --git a/arch/arm64/boot/dts/qcom/qcm6490-fairphone-fp5.dts b/arch/arm64/boot/dts/qcom/qcm6490-fairphone-fp5.dts
index f5bd51806819..e7be17844da1 100644
--- a/arch/arm64/boot/dts/qcom/qcm6490-fairphone-fp5.dts
+++ b/arch/arm64/boot/dts/qcom/qcm6490-fairphone-fp5.dts
@@ -712,7 +712,7 @@ &mdss_dp {
 };
 
 &mdss_dp_out {
-	data-lanes = <0 1>;
+	data-lanes = <0 1 2 3>;
 	remote-endpoint = <&usb_dp_qmpphy_dp_in>;
 };
 
@@ -1344,6 +1344,7 @@ &usb_1_qmpphy {
 	vdda-phy-supply = <&vreg_l6b>;
 	vdda-pll-supply = <&vreg_l1b>;
 
+	mode-switch;
 	orientation-switch;
 
 	status = "okay";


The output of the dp_debug file shows it's trying to use 4 lanes:

        name = msm_dp
        drm_dp_link
                rate = 540000
                num_lanes = 4
                capabilities = 1
        dp_panel_info:
                active = 0x0
                back_porch = 0x0
                front_porch = 0x0
                sync_width = 0x0
                active_low = 0x0
                h_skew = 0
                refresh rate = 0
                pixel clock khz = 0
                bpp = 0
        dp_link:
                test_requested = 128
                num_lanes = 4
                bw_code = 20
                lclk = 540000000
                v_level = 2
                p_level = 0

But the monitor stays black and the following appears in dmesg:
(starts with plugging in a dongle, ends with unplugging it again)

[ 1773.538161] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[ 1773.538197] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 1
[ 1773.540215] xhci-hcd xhci-hcd.2.auto: hcc params 0x0230fe65 hci version 0x110 quirks 0x0000008000000010
[ 1773.540260] xhci-hcd xhci-hcd.2.auto: irq 185, io mem 0x0a600000
[ 1773.540372] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[ 1773.540384] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 2
[ 1773.540396] xhci-hcd xhci-hcd.2.auto: Host supports USB 3.0 SuperSpeed
[ 1773.540524] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 6.08
[ 1773.540534] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1773.540541] usb usb1: Product: xHCI Host Controller
[ 1773.540547] usb usb1: Manufacturer: Linux 6.8.0-00058-g113103fa3b95 xhci-hcd
[ 1773.540554] usb usb1: SerialNumber: xhci-hcd.2.auto
[ 1773.540999] hub 1-0:1.0: USB hub found
[ 1773.541028] hub 1-0:1.0: 1 port detected
[ 1773.542010] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[ 1773.542146] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003, bcdDevice= 6.08
[ 1773.542162] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 1773.542174] usb usb2: Product: xHCI Host Controller
[ 1773.542183] usb usb2: Manufacturer: Linux 6.8.0-00058-g113103fa3b95 xhci-hcd
[ 1773.542193] usb usb2: SerialNumber: xhci-hcd.2.auto
[ 1773.543241] hub 2-0:1.0: USB hub found
[ 1773.543282] hub 2-0:1.0: 1 port detected
[ 1775.563969] [drm:dp_ctrl_link_train] *ERROR* max v_level reached
[ 1775.564031] [drm:dp_ctrl_link_train] *ERROR* link training #1 failed. ret=-11
[ 1775.597965] [drm:dp_display_process_hpd_high] *ERROR* failed to complete DP link training
[ 1775.598149] [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
[ 1776.632081] [drm:dp_ctrl_link_train] *ERROR* max v_level reached
[ 1776.632145] [drm:dp_ctrl_link_train] *ERROR* link training #1 failed. ret=-11
[ 1776.662978] [drm:dp_display_process_hpd_high] *ERROR* failed to complete DP link training
[ 1776.663039] [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
[ 1777.717501] [drm:dp_ctrl_link_train] *ERROR* max v_level reached
[ 1777.717524] [drm:dp_ctrl_link_train] *ERROR* link training #1 failed. ret=-11
[ 1777.751427] [drm:dp_display_process_hpd_high] *ERROR* failed to complete DP link training
[ 1777.751518] [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
[ 1778.793550] [drm:dp_ctrl_link_train] *ERROR* max v_level reached
[ 1778.793617] [drm:dp_ctrl_link_train] *ERROR* link training #1 failed. ret=-11
[ 1778.827260] [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
[ 1778.827334] [drm:dp_display_process_hpd_high] *ERROR* failed to complete DP link training
[ 1779.279889] xhci-hcd xhci-hcd.2.auto: remove, state 1
[ 1779.279942] usb usb2: USB disconnect, device number 1
[ 1779.311920] xhci-hcd xhci-hcd.2.auto: USB bus 2 deregistered
[ 1779.311987] xhci-hcd xhci-hcd.2.auto: remove, state 4
[ 1779.312019] usb usb1: USB disconnect, device number 1
[ 1779.317772] xhci-hcd xhci-hcd.2.auto: USB bus 1 deregistered

Regards
Luca


> ...
>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
> Neil Armstrong (7):
>       dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp: Add mode-switch
>       phy: qcom: qmp-combo: store DP phy power state
>       phy: qcom: qmp-combo: introduce QPHY_MODE
>       phy: qcom: qmp-combo: register a typec mux to change the QPHY_MODE
>       arm64: dts: qcom-sm8550: allow 4 lanes for DisplayPort and enable QMP PHY mode-switch
>       arm64: dts: qcom-sm8650: allow 4 lanes for DisplayPort and enable QMP PHY mode-switch
>       arm64: dts: qcom-mode-switch: allow 4 lanes for DisplayPort and enable QMP PHY mode-switch
>
>  .../phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml         |   5 +
>  .../dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts     |   6 +-
>  arch/arm64/boot/dts/qcom/sm8550-hdk.dts            |   3 +-
>  arch/arm64/boot/dts/qcom/sm8550-qrd.dts            |   3 +-
>  arch/arm64/boot/dts/qcom/sm8650-qrd.dts            |   3 +-
>  drivers/phy/qualcomm/phy-qcom-qmp-combo.c          | 168 +++++++++++++++++++--
>  6 files changed, 173 insertions(+), 15 deletions(-)
> ---
> base-commit: b321c0e8ca754d8cd9f23ceba958e3ea93c6519e
> change-id: 20240229-topic-sm8x50-upstream-phy-combo-typec-mux-31b5252513c9
>
> Best regards,

