External USB C Monitor not working

[wrzomar]

I am seeing the same problem. I have a new Pinebook Pro running Manjaro 5.7.19-1-MANJARO-ARM #1 SMP Wed Sep 2 20:43:09 +03 2020 aarch64 GNU/Linux. I am unable to get it to detect a Dell UltraSharp 27 4K USB-C Monitor - U2720Q external display plugged in via the included USB-C cable. Charging works, but video out does not.

The user manual says the monitor supports: 1 x USB Type-C (Alternate mode with DisplayPort 1.4, USB 3.0 upstream port, Power Delivery PD up to 90 W).

When I plug the cable into the Pinebook Pro, dmesg shows the following:

Code:

[Mon Sep 21 10:39:06 2020] usb 7-1.5: USB disconnect, device number 11
[Mon Sep 21 10:39:06 2020] cdn-dp fec00000.dp: [drm:cdn_dp_pd_event_work [rockchipdrm]] Not connected. Disabling cdn
[Mon Sep 21 10:39:06 2020] cdn-dp fec00000.dp: [drm:cdn_dp_pd_event_work [rockchipdrm]] Not connected. Disabling cdn
[Mon Sep 21 10:39:30 2020] cdn-dp fec00000.dp: [drm:cdn_dp_pd_event_work [rockchipdrm]] Not connected. Disabling cdn
[Mon Sep 21 10:39:30 2020] cdn-dp fec00000.dp: [drm:cdn_dp_pd_event_work [rockchipdrm]] Not connected. Disabling cdn
[Mon Sep 21 10:39:30 2020] typec_displayport port0-partner.0: No compatible pin configuration found:0000 -> 0014, 001c <- 0000
[Mon Sep 21 10:39:30 2020] usb 7-1: new high-speed USB device number 12 using xhci-hcd
[Mon Sep 21 10:39:30 2020] usb 7-1: New USB device found, idVendor=0451, idProduct=8442, bcdDevice= 1.00
[Mon Sep 21 10:39:30 2020] usb 7-1: New USB device strings: Mfr=0, Product=0, SerialNumber=1
[Mon Sep 21 10:39:30 2020] usb 7-1: SerialNumber: 52010851800D
[Mon Sep 21 10:39:30 2020] hub 7-1:1.0: USB hub found
[Mon Sep 21 10:39:30 2020] hub 7-1:1.0: 6 ports detected
[Mon Sep 21 10:39:30 2020] usb 8-1: new SuperSpeed Gen 1 USB device number 6 using xhci-hcd
[Mon Sep 21 10:39:30 2020] usb 8-1: New USB device found, idVendor=0451, idProduct=8440, bcdDevice= 1.10
[Mon Sep 21 10:39:30 2020] usb 8-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[Mon Sep 21 10:39:30 2020] hub 8-1:1.0: USB hub found
[Mon Sep 21 10:39:30 2020] hub 8-1:1.0: 4 ports detected
[Mon Sep 21 10:39:31 2020] usb 7-1.5: new high-speed USB device number 13 using xhci-hcd
[Mon Sep 21 10:39:31 2020] usb 7-1.5: New USB device found, idVendor=0451, idProduct=82ff, bcdDevice= 2.00
[Mon Sep 21 10:39:31 2020] usb 7-1.5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[Mon Sep 21 10:39:31 2020] hid-generic 0003:0451:82FF.000A: hiddev97,hidraw2: USB HID v1.11 Device [HID 0451:82ff] on usb-xhci-hcd.1.auto-1.5/input0

I have tried rotating the cable and also booting with it plugged in. The monitor works in a Macbook Air (2018) but not with the Pinebook. As this is still on the 5.7 kernel, it seems unrelated to the regression in the 5.8 kernel. I posted on the Manjaro forums but they didn't know how to debug it. Any suggestions?

You can try the old default OS, but I don't know if the image with Mrfixit2001's Debian OS has USB-c fully working. Almost month ago, I've switched to Manjaro and I wanted to have this older OS on a SD card, but WiFi wasn't working (I don't remember if it was working when I got PBP with preinstalled OS, but I think it was) and the update script wasn't working either when I've tried to update using Ethernet dongle. The update script was comparing installed version with version string from Mrfixit2001 github, then it would download whatever is needed from Mrfixit2001's svn. Try to avoid doing 'apt upgrade'. You can try to contact Mrfixit2001. If your monitor will not work with PBP on Mrfixit2001 Debian Desktop version 2.0, then you can try one of the compatible HDMI adapters. If your monitor would work with Mrfixit2001 system, then there is hope it will work someday with Manjaro. But I'm not suggesting using this Debian Desktop as a daily driver, because it will slowly deteriorate with every 'apt upgrade'.