Display Port over USB-C

marcvg

Does Solus support DP over USB-C? It doesn't seem to detect the display.

riffer

marcvg

Yes. I use it to hook up my X1 Carbon to my Dell monitor.

Check that your USB-C port and your cable actually support DP over USB-C.

On my Dell the screen shows a message if nothing comes over the usb-c connection.

Original-Syn

Yep, it is how I connect my monitor to my work laptop. Just make sure the USB-C supports it.

While having it connected you can run the following to give more details...
inxi -JJ and inxi -a --usb

TraceyC

Solus supports DP over USB-C in that the kernel has driver support for it. The laptop I'm using right now is hooked up to a dock via USB-C, and the dock outputs displays to DP and HDMI.

We need more information to narrow down what's happening.

What desktop environment are you using (Budgie, etc)
What do you mean by not detecting the display? Can you provide more detail? Does the monitor show that it has no input, do you see a cursor or not?
The output of inxi that Original-Syn asked for will be helpful as well.

marcvg

TraceyC I'm using Budgie. The laptop does not detect any monitor when connected via USB-C to DP.

marc@workstation-marc ~ $ inxi -JJ
USB:
  Hub-1: 1-0:1 info: hi-speed hub with single TT ports: 1 rev: 2.0
  Hub-2: 2-0:1 info: super-speed hub ports: 2 rev: 3.1
  Hub-3: 2-1:2 info: VIA Labs USB3.0 Hub ports: 4 rev: 3.1
  Hub-4: 2-1.4:3 info: VIA Labs USB3.0 Hub ports: 4 rev: 3.1
  Device-1: 2-1.4.2:4 info: ASIX AX88179 Gigabit Ethernet
    type: communication,CDC-data rev: 3.2
  Hub-5: 3-0:1 info: hi-speed hub with single TT ports: 12 rev: 2.0
  Hub-6: 3-1:2 info: VIA Labs USB2.0 Hub ports: 5 rev: 2.1
  Device-1: 3-1.2:5 info: Dell Universal Receiver type: keyboard,mouse,HID
    rev: 2.0
  Device-2: 3-1.3:7 info: GN Netcom Jabra Evolve2 65 Deskstand type: HID
    rev: 2.0
  Hub-7: 3-1.4:9 info: VIA Labs USB2.0 Hub ports: 4 rev: 2.1
  Hub-8: 3-1.4.1:12 info: Cambridge Silicon Radio Mpow HC5 Headset in
    charging mode - USB Hub ports: 4 rev: 2.0
  Device-1: 3-1.4.1.1:13 info: GN Netcom Jabra Link 380 type: audio,HID
    rev: 2.0
  Device-2: 3-1.5:11 info: VIA Labs USB Billboard Device type: billboard
    rev: 2.0
  Device-3: 3-3:3 info: ASUSTek N-KEY Device type: keyboard rev: 2.0
  Device-4: 3-5:14 info: VIA Labs USB-C dongle type: billboard rev: 2.0
  Device-5: 3-7:6 info: Sonix USB2.0 FHD UVC WebCam type: video rev: 2.0
  Device-6: 3-9:8 info: ASUSTek ITE Device(8295) type: keyboard rev: 2.0
  Device-7: 3-10:10 info: Intel AX211 Bluetooth type: bluetooth rev: 2.0
  Hub-9: 4-0:1 info: super-speed hub ports: 4 rev: 3.1

marc@workstation-marc ~ $ inxi -a --usb
USB:
  Hub-1: 1-0:1 info: hi-speed hub with single TT ports: 1 rev: 2.0
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 1d6b:0002
    class-ID: 0900
  Hub-2: 2-0:1 info: super-speed hub ports: 2 rev: 3.1
    speed: 20 Gb/s (2.33 GiB/s) lanes: 2 mode: 3.2 gen-2x2 chip-ID: 1d6b:0003
    class-ID: 0900
  Hub-3: 2-1:2 info: VIA Labs USB3.0 Hub ports: 4 rev: 3.1
    speed: 5 Gb/s (596.0 MiB/s) lanes: 1 mode: 3.2 gen-1x1 chip-ID: 2109:0817
    class-ID: 0900
  Hub-4: 2-1.4:3 info: VIA Labs USB3.0 Hub ports: 4 rev: 3.1
    speed: 5 Gb/s (596.0 MiB/s) lanes: 1 mode: 3.2 gen-1x1 chip-ID: 2109:0817
    class-ID: 0900
  Device-1: 2-1.4.2:4 info: ASIX AX88179 Gigabit Ethernet
    type: communication,CDC-data driver: cdc_ncm interfaces: 2 rev: 3.2
    speed: 5 Gb/s (596.0 MiB/s) lanes: 1 mode: 3.2 gen-1x1 power: 184mA
    chip-ID: 0b95:1790 class-ID: 0a00 serial: 001ED7A6
  Hub-5: 3-0:1 info: hi-speed hub with single TT ports: 12 rev: 2.0
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 1d6b:0002
    class-ID: 0900
  Hub-6: 3-1:2 info: VIA Labs USB2.0 Hub ports: 5 rev: 2.1
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 2109:2817
    class-ID: 0900
  Device-1: 3-1.2:5 info: Dell Universal Receiver type: keyboard,mouse,HID
    driver: hid-generic,usbhid interfaces: 3 rev: 2.0 speed: 12 Mb/s (1.4 MiB/s)
    lanes: 1 mode: 1.1 power: 100mA chip-ID: 413c:301d class-ID: 0300
  Device-2: 3-1.3:7 info: GN Netcom Jabra Evolve2 65 Deskstand type: HID
    driver: jabra,usbhid interfaces: 1 rev: 2.0 speed: 12 Mb/s (1.4 MiB/s)
    lanes: 1 mode: 1.1 power: 500mA chip-ID: 0b0e:c0dd class-ID: 0300
    serial: 07415357503902
  Hub-7: 3-1.4:9 info: VIA Labs USB2.0 Hub ports: 4 rev: 2.1
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 2109:2817
    class-ID: 0900
  Hub-8: 3-1.4.1:12 info: Cambridge Silicon Radio Mpow HC5 Headset in
    charging mode - USB Hub ports: 4 rev: 2.0 speed: 12 Mb/s (1.4 MiB/s)
    lanes: 1 mode: 1.1 power: 100mA chip-ID: 0a12:4010 class-ID: 0900
  Device-1: 3-1.4.1.1:13 info: GN Netcom Jabra Link 380 type: audio,HID
    driver: jabra,snd-usb-audio,usbhid interfaces: 4 rev: 2.0
    speed: 12 Mb/s (1.4 MiB/s) lanes: 1 mode: 1.1 chip-ID: 0b0e:24ca
    class-ID: 0300 serial: 305075F02137
  Device-2: 3-1.5:11 info: VIA Labs USB Billboard Device type: billboard
    driver: N/A interfaces: 1 rev: 2.0 speed: 480 Mb/s (57.2 MiB/s) lanes: 1
    mode: 2.0 power: 100mA chip-ID: 2109:8884 class-ID: 1100
    serial: 0000000000000001
  Device-3: 3-3:3 info: ASUSTek N-KEY Device type: keyboard
    driver: asus,usbhid interfaces: 1 rev: 2.0 speed: 12 Mb/s (1.4 MiB/s)
    lanes: 1 mode: 1.1 power: 100mA chip-ID: 0b05:19b6 class-ID: 0301
  Device-4: 3-5:14 info: VIA Labs USB-C dongle type: billboard driver: N/A
    interfaces: 1 rev: 2.0 speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0
    power: 100mA chip-ID: 2109:0100 class-ID: 1100 serial: 0000000000000001
  Device-5: 3-7:6 info: Sonix USB2.0 FHD UVC WebCam type: video
    driver: uvcvideo interfaces: 4 rev: 2.0 speed: 480 Mb/s (57.2 MiB/s)
    lanes: 1 mode: 2.0 power: 500mA chip-ID: 3277:0018 class-ID: 0e02
  Device-6: 3-9:8 info: ASUSTek ITE Device(8295) type: keyboard
    driver: hid-generic,usbhid interfaces: 1 rev: 2.0 speed: 12 Mb/s (1.4 MiB/s)
    lanes: 1 mode: 1.1 power: 100mA chip-ID: 0b05:193b class-ID: 0301
  Device-7: 3-10:10 info: Intel AX211 Bluetooth type: bluetooth
    driver: btusb interfaces: 2 rev: 2.0 speed: 12 Mb/s (1.4 MiB/s) lanes: 1
    mode: 1.1 power: 100mA chip-ID: 8087:0033 class-ID: e001
  Hub-9: 4-0:1 info: super-speed hub ports: 4 rev: 3.1
    speed: 10 Gb/s (1.16 GiB/s) lanes: 1 mode: 3.2 gen-2x1 chip-ID: 1d6b:0003
    class-ID: 0900
marc@workstation-marc ~ $

TraceyC

Those commands shows the hardware that's detected, but not the displays. Do you see the port / hub that the display is connected to?

This will list all displays the kernel can see, what's the output of this:

xrandr --listactivemonitors

I don't remember if xrandr is installed by default. If not, you can install it from the repo.

palto42

Some docks (and maybe monitors?) require DisplayLink drivers, which are not supported by Solus. I recently tried the HP Dock G2 without success for that reason. Now I have the HP Dock G5 which works fine with Solus (uses DisplayPort Alternate Mode).

But the DisplayPort is not shown with inxi -a --usb, I think because in DP alt mode just uses some signal lines of the USB-C connector for native DP and is not a USB device as such.

TraceyC

palto42 Some docks (and maybe monitors?) require DisplayLink drivers,

marcvg hasn't said they're using a dock, it sounds like just a USB-C cable. DP is one of the signals passed through via the USB-C standard.

palto42

TraceyC Not every USB-C port passes through DisplayPort signals, it needs to support the DP Alternate Mode.

TraceyC

palto42

Unfortunately true.

marcvg,
To see if the port itself supports passing DP signals, you might try booting another Linux ISO, like Ubuntu, and connect that monitor using the same port. If it works with Ubuntu, the port isn't the problems, it's software (like the kernel, maybe). Let us know what your results are.

marcvg

Hi again,

I managed to briefly get it to work. I unplugged my usb-c dock and used that usb-c port to connect to the monitor, and it worked. I ran the xrandr command:

marc@workstation-marc ~ $ xrandr --listactivemonitors Monitors: 2 0: +*DP-1 3840/1016x2160/571+0+0 DP-1 1: +eDP-1 2560/345x1600/215+3840+0 eDP-1

The display showed uo in the display settings. However, when I unplugged it to try my 2nd USB-C port it never showed up in the display settings again (even when the xrandr command still listed the monitor. Even when reconnecting to the first USB-C port.

Edit: OK, so rebooting with the monitor connected to my first USB-C port (left side) works! The second USB-C port does not seem to support the display cable (if that makes sense?).

TraceyC

marcvg The second USB-C port does not seem to support the display cable (if that makes sense?).

That makes sense. Sadly, the USB-C specifications are so loose, that it's resulted in a mess of confusion. There is no way, outside of poring over specs for each individual computer and its ports, to know what each port supports. And some manufacturers, especially cheap ones, don't make it clear or might not even detail things at all.

For anyone interested in the rabbit hole, Ars Technica had an article recently, "Microsoft wants a version of USB-C that “just works” consistently across all PCs" which covers the confusion of what ports support what.

Original-Syn

TraceyC Rare that I agree with much from Microsoft, but I 100% agree on this. I worked on the team at Dell in the 90s that had to build firmware and initial drivers. It sucked then, and that was just the initial simple version. I was pleased that I moved to a different team shortly after, as they partnered with IBM to build it out.