[BUG] Vive display not detected

[kroltan]

Describe the bug
I have a HTC Vive. I changed from an NVIDIA GPU to the Radeon 7900XTX. Now I can't get into VR when the headset is connected through the Link Box. If the Link Box is bypassed, then VR works.

To Reproduce
Steps to reproduce the behavior:

1. Make sure the HMD is plugged in through the Link Box
2. Start SteamVR
3. Steam will warn about error 109
4. The SteamVR window will open on the desktop, with the message "Failed to connect to headset display", error code 496
5. Close SteamVR
6. Connect the HMD's 3-in-1 cable's HDMI connection directly to your GPU, not the Link Box
7. Start SteamVR
8. Observe it works.

Expected behavior
The Link Box may be used to route the HDMI connection, and the HMD operates successfully in that case.

System Information (please complete the following information):
Please use the latest Steam beta client and SteamVR beta for your bug reports!

• Steam client version (build number or date): 1720650399 (Wed, Jul 10 6:09 PM UTC -03:00)
• SteamVR version: 2.6.2
• Distribution (e.g. Ubuntu): Manjaro (KDE, kernel 6.8.12-3-MANJARO)
• Steam runtime diagnostics: [generate via Help -> Steam Runtime Diagnostics in the Steam client]
• Steam and SteamVR logs: steam-logs.tar.gz
• Minidumps: steam-minidumps.tar.gz

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context

Got the hint to bypass the Link Box from #636 (comment), so it might be a related issue.

I tried this in both X and Wayland sessions of KDE Plasma.

If I run xrandr, then it tracks with when SteamVR can find the headset:

• If going through link box, no HDMI connection in xrandr output;
• If directly on GPU, a HDMI connection appears in xrandr.

It is not a defect of the HDMI cable, I have tried with a spare I have and it also is not detected.

[kroltan]

Just tried switching to the SteamVR temp_v1.27.5 branch and it is working fine. I'll keep using this while it lasts if this isn't fixed or a more legit workaround is found.

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In fact, it even has better tracking latency, as when I connected the headset directly to my GPU with the production branch, I felt like the camera was "smoothed" or lagged behind my head movements by a couple arcseconds. In the temp branch it is pretty much instant, or at least on par with the Windows experience.

[lilithwhite]

I have the same issue but unfortunately the temp branch doesn't solve it for me, I still get the unable to detect headset issue with it. So far the only fix has been to connect the headset directly to my PC without the link box.

[Benik3]

I can confirm this (HTC Vive is not detected through LinkBox on my 7900 XTX).
Connecting the headset directly to the GPU is not a solution, because there is a lag between motion and picture (which makes me sick)...
The problem exists also on Windows.

[Alex-G]

Same issue here :(

[Benik3]

I solved mine with using miniDP to DP cable instead of HDMI...