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

[Neil Armstrong <neil.armstrong@linaro.org>]

On 15/03/2024 18:19, Luca Weiss wrote:
> 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

Interesting #1 means the 4 lanes are not physically connected to the other side,
perhaps QCM6490/SC7280 requires a specific way to enable the 4 lanes in the PHY,
or some fixups in the init tables.

Abhinav, any suggestions ?

Neil

> [ 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,
>