HDMI not outputting to monitor

Tachyon
1

Hi,

I have plugged my usb c hub with external power into my tachyon’s usb1 connector and no video is showing on the monitor. I tried with multiple monitors and multiple usb c hubs and a usb c to hdmi adapter. I also bought the ugreen usb c hub from amazon and that is not working either. I tried flashing both desktop and headless variants but I still see no display getting connected when I try running modetest -M msm_drm over serial/ssh. I get these errors in journalctl:

Jul 08 21:56:04 tachyon-ecb0ee32 kernel: msm-dwc3 a600000.ssusb: DWC3 exited from low power mode
Jul 08 21:56:04 tachyon-ecb0ee32 kernel: [drm:dp_aux_configure_aux_switch][msm-dp-err][315 ]failed to configure fsa4480 i2c device (-5)
Jul 08 21:56:04 tachyon-ecb0ee32 kernel: [drm:dp_display_usbpd_configure_cb][msm-dp-err][315 ]aux_switch failed: -5, but continuing
Jul 08 21:56:04 tachyon-ecb0ee32 kernel: [drm:dp_power_clk_enable][msm-dp-info][315 ]core:on link:off strm0:off strm1:off
Jul 08 21:56:04 tachyon-ecb0ee32 kernel: [drm:dp_display_host_init][msm-dp-info][315 ][OK]
Jul 08 21:56:08 tachyon-ecb0ee32 kernel: [drm:dp_display_host_ready][msm-dp-info][236 ][OK]
Jul 08 21:56:10 tachyon-ecb0ee32 kernel: [drm:dp_panel_read_dpcd][msm-dp-err][236 ]error reading DP_TRAINING_AUX_RD_INTERVAL
Jul 08 21:56:10 tachyon-ecb0ee32 kernel: [drm:dp_panel_read_sink_caps][msm-dp-err][236 ]panel dpcd read failed/incorrect, set default params
Jul 08 21:56:10 tachyon-ecb0ee32 kernel: [drm:dp_panel_read_edid][msm-dp-err][236 ]EDID read failed
Jul 08 21:56:10 tachyon-ecb0ee32 kernel: [drm:dp_panel_read_sink_caps][msm-dp-err][236 ]panel edid read failed, set failsafe mode
Jul 08 21:56:12 tachyon-ecb0ee32 kernel: [drm:dp_link_parse_sink_count][msm-dp-err][236 ]failed to read sink count
Jul 08 21:56:14 tachyon-ecb0ee32 kernel: [drm:dp_link_parse_sink_status_field][msm-dp-err][236 ]DP link status read failed
Jul 08 21:56:16 tachyon-ecb0ee32 kernel: [drm:dp_link_process_request][msm-dp-info][236 ]event: DP_LINK_STATUS_UPDATED
Jul 08 21:56:16 tachyon-ecb0ee32 kernel: [drm:dp_power_clk_enable][msm-dp-info][236 ]core:on link:on strm0:off strm1:off
Jul 08 21:56:17 tachyon-ecb0ee32 kernel: [drm:dp_power_clk_enable][msm-dp-info][236 ]core:on link:off strm0:off strm1:off
Jul 08 21:56:17 tachyon-ecb0ee32 kernel: [drm:dp_display_attention_work][msm-dp-info][236 ]Hpd off, not handling any attention
Jul 08 21:56:17 tachyon-ecb0ee32 kernel: [drm:dp_display_host_unready][msm-dp-info][14090][OK]

I’m suspecting that all my usb c adapters are incompatible and the ugreen one I bought (Amazon.com: UGREEN Revodok 105 USB C Hub 5 in 1 Multiport Adapter 4K HDMI, 100W Power Delivery, 3 USB-A Data Ports, USB C Dongle for MacBook Pro/Air, iPad Pro, iMac, iPhone 15 Pro/Pro Max, XPS, Thinkpad : Electronics) isn’t the same one from the kickstarter. Can anyone confirm that this usb c hub is also incompatible? Is there anything else I can try? Thanks

2

Hey kazi1!

Some quick questions:

  • what version of software are you using? Can you check this file?

cat /etc/particle/distro_versions.json

  • is the USB-C hub plugged in when you boot or plugged in afterwards?

  • what power supply are you putting into the USB-C hub?

  • what monitor are you connecting to and what resolution?

  • is the battery plugged in at the same time?

The good news is that I have that exact USB-C hub and it works well here, so I suspect we just need to figure out the gap.

Thanks,

NIck

3

Thanks @mrlambchop

I am seeing this:

root@tachyon-ecb0ee32:~# cat /etc/particle/distro_versions.json
{
"distro": {
"stack": "ubuntu-desktop",
"version": "1.0.141",
"variant": "desktop",
"board": "formfactor_dvt",
"region": "NA"
},
"src": {
"ubuntu_20_04": "image-79-fe6d3139d",
"quectel_bp_fw": "1.0.11"
}

I’ve tried booting with both the usb c hub plugged in and without it plugged in, and have tried combinations with and without the power supply plugged in. I am using the power supply from the kickstarter addon.

Currently I am connecting to a Dell P2419H at 1920x1080 60Hz which works for my other systems

I do have the 3 cell battery plugged in

4

FWIW, I had trouble with my adapter and it only worked after using the first USB-C port and having the battery plugged in. I am using headless Ubuntu. Which may make the difference.