usb-c HDMI output issue

Tiget1998 · November 10, 2021

Hello there,

Recently, this morning actually, my usb-c dongle(s) won't give any HDMI output from my laptop to an external screen. Other usb-c functionalities run perfectly fine(besides ethernet which is capped at 100 Mbps), only the HDMI does not want to work on my laptop, I tried other laptops and they work perfectly fine.

I'm running a dual boot setup for about a year now and me thinking I somehow messed up in Linux, I tried to go to Windows to check whether it was Linux issue, I did not get any HDMI output from windows either. So I thought this would somehow be a hardware related issue, I checked with other laptops but the dongle, including HDMI should work perfectly fine. So I did some troubleshooting and from what I can understand, everything should work completely as everything on the motherboard appears to be recognized and working. However I have narrowed it down to what I believe is the issue and I lack the know how on how to solve it.

My usb-c dongle should connect to bus 004 as that is the thunderbolt-3 connection line it should route the HDMI to. I know this because I had to troubleshoot an ethernet issue before. This is what the output should look like from lsusb:

Bus 004 Device 004: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter
Bus 004 Device 003: ID 2109:0813 VIA Labs, Inc. VL813 Hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 27c6:55b4 Shenzhen Goodix Technology Co.,Ltd. Fingerprint Reader
Bus 001 Device 003: ID 5986:114e Acer, Inc Integrated Camera
Bus 001 Device 007: ID 2109:0101 VIA Labs, Inc. USB 2.0 BILLBOARD             
Bus 001 Device 006: ID 2109:2813 VIA Labs, Inc. VL813 Hub
Bus 001 Device 005: ID 8087:0aaa Intel Corp. Bluetooth 9460/9560 Jefferson Peak (JfP)
Bus 001 Device 002: ID 046d:c539 Logitech, Inc. USB Receiver
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

This is what the lsusb looks like now:

Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 006: ID 27c6:55b4 Shenzhen Goodix Technology Co.,Ltd. Fingerprint Reader
Bus 001 Device 004: ID 5986:114e Acer, Inc Integrated Camera
Bus 001 Device 023: ID 2109:0101 VIA Labs, Inc. USB 2.0 BILLBOARD             
Bus 001 Device 022: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter
Bus 001 Device 021: ID 2109:2813 VIA Labs, Inc. VL813 Hub
Bus 001 Device 008: ID 8087:0aaa Intel Corp. Bluetooth 9460/9560 Jefferson Peak (JfP)
Bus 001 Device 002: ID 046d:c539 Logitech, Inc. USB Receiver
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Somehow all my dongle connections have been shifted to device 02x and the gigabit connection and the VL813 are moved to bus 001 instead of 003 and 004. As bus 003 and 004 are the high speed connections, it explains why there is no HDMI output, and after confirming my ideas, the ethernet is limited to 100 Mbps on this bus due to lack of speed which makes sense.

So what I believe needs to happen is, I somehow need to route this dongle back to bus 004 for proper functionality, issue being I lack the know how on how to do it or if this is even possible. Considering this issue is not limited to Linux but also Windows it might still be hardware related or somehow baked into the BIOS?

Some specs:

System:    Host: xxxx Kernel: 5.14.16-arch1-1 x86_64 bits: 64 compiler: gcc v: 11.1.0 Desktop: KDE Plasma 5.23.2
           Distro: EndeavourOS base: Arch Linux
Machine:   Type: Laptop System: LENOVO product: 81NX v: Lenovo Yoga S740-15IRH serial: <superuser required>
           Mobo: LENOVO model: LNVNB161216 v: SDK0R32862 WIN serial: <superuser required> UEFI: LENOVO v: BKCN24WW(V1.06)
           date: 06/08/2021
Battery:   ID-1: BAT1 charge: 62.8 Wh (98.9%) condition: 63.5/69.0 Wh (92.0%) volts: 17.3 min: 15.4
           model: 0x53 0x75 0x6E 0x77 0x6F 0x64 0x PABAS0241231 status: Unknown
           Device-1: hidpp_battery_0 model: Logitech G603 Wireless Gaming Mouse charge: 55% (should be ignored)
           status: Discharging
CPU:       Info: 6-Core model: Intel Core i7-9750H bits: 64 type: MT MCP arch: Kaby Lake note: check rev: A cache: L2: 12 MiB
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 62431
           Speed: 800 MHz min/max: 800/4500 MHz Core speeds (MHz): 1: 800 2: 807 3: 801 4: 817 5: 815 6: 800 7: 800 8: 803
           9: 807 10: 807 11: 800 12: 800
Graphics:  Device-1: Intel CoffeeLake-H GT2 [UHD Graphics 630] vendor: Lenovo driver: i915 v: kernel bus-ID: 00:02.0
           Device-2: NVIDIA TU117M [GeForce GTX 1650 Mobile / Max-Q] vendor: Lenovo driver: nvidia v: 495.44 bus-ID: 01:00.0
           Device-3: Acer Integrated Camera type: USB driver: uvcvideo bus-ID: 1-4:4
           Display: x11 server: X.org 1.20.13 driver: loaded: modesetting,nvidia resolution: <missing: xdpyinfo>
           OpenGL: renderer: Mesa Intel UHD Graphics 630 (CFL GT2) v: 4.6 Mesa 21.2.4 direct render: Yes
Audio:     Device-1: Intel Cannon Lake PCH cAVS vendor: Lenovo driver: sof-audio-pci-intel-cnl bus-ID: 00:1f.3
           Sound Server-1: ALSA v: k5.14.16-arch1-1 running: yes
           Sound Server-2: JACK v: 1.9.19 running: no
           Sound Server-3: PulseAudio v: 15.0 running: yes
           Sound Server-4: PipeWire v: 0.3.39 running: yes
Network:   Device-1: Intel Cannon Lake PCH CNVi WiFi driver: iwlwifi v: kernel bus-ID: 00:14.3
           IF: wlan0 state: up mac: c0:b8:83:d7:5e:e2
           Device-2: Realtek RTL8153 Gigabit Ethernet Adapter type: USB driver: r8152 bus-ID: 1-3.1:22
           IF: enp0s20f0u3u1 state: down mac: 34:29:8f:91:5d:ad
Bluetooth: Device-1: Intel Bluetooth 9460/9560 Jefferson Peak (JfP) type: USB driver: btusb v: 0.8 bus-ID: 1-14:8
           Report: rfkill ID: hci0 rfk-id: 3 state: down bt-service: enabled,running rfk-block: hardware: no software: yes
           address: see --recommends
Drives:    Local Storage: total: 953.87 GiB used: 112.86 GiB (11.8%)
           ID-1: /dev/nvme0n1 vendor: Samsung model: MZVLB1T0HBLR-000L2 size: 953.87 GiB temp: 38.9 C
Partition: ID-1: / size: 450.71 GiB used: 112.84 GiB (25.0%) fs: ext4 dev: /dev/nvme0n1p5
           ID-2: /boot/efi size: 256 MiB used: 29.8 MiB (11.6%) fs: vfat dev: /dev/nvme0n1p1
Swap:      Alert: No swap data was found.
Sensors:   System Temperatures: cpu: 61.0 C mobo: N/A
           Fan Speeds (RPM): N/A
Repos:     Packages: 1288

If someone has any idea on how to tackle this issue, I'm happy to hear it and appreciate the help.

AbydosOne · November 10, 2021

26 minutes ago, Tiget1998 said:

Recently, this morning actually, my usb-c dongle(s) won't give any HDMI output from my laptop to an external screen. Other usb-c functionalities run perfectly fine(besides ethernet which is capped at 100 Mbps), only the HDMI does not want to work on my laptop, I tried other laptops and they work perfectly fine.

It sounds like one or both pairs of high-speed differential signal lines are compromised in some way. In most dongles, one pair is used for USB 3.x speeds and the other is used for DisplayPort alt-mode (converted to HDMI by the dongle; there is an alt-mode for straight HDMI, but I haven't seen it explicitly used anywhere, so I assume everything is DP still). The USB 2.0 signals are sent over a different pair (and are entirely separate from 3.x signal and data), hence why they still work.

What are the exact models of dongle and laptop?

Tiget1998 · November 10, 2021

48 minutes ago, AbydosOne said:

It sounds like one or both pairs of high-speed differential signal lines are compromised in some way. In most dongles, one pair is used for USB 3.x speeds and the other is used for DisplayPort alt-mode (converted to HDMI by the dongle; there is an alt-mode for straight HDMI, but I haven't seen it explicitly used anywhere, so I assume everything is DP still). The USB 2.0 signals are sent over a different pair (and are entirely separate from 3.x signal and data), hence why they still work.

What are the exact models of dongle and laptop?

Laptop model is also in the inxi output: Lenovo Yoga/Ideapad S740-15IRH. And the dongle is a generic CableTime 6-1 usb-c hub, article number SB2119R, and EAN 7440857976982. Even though its one of the cheapest, it has held up to standards for almost 2 years now.

Just to be clear (because the Lenovo technician/rep did not understand at all) that the dongle works 100% including HDMI on other laptops/smartphones.