Editing Openai/69492970-fd84-8012-81ad-fad51507b9fe (section)

=== Assistant: Ahh — that detail changes everything, and yeah, this makes total sense now. ===
Ahh — that detail changes everything, and yeah, this makes total sense now.
You’re not fighting “GPU priority” at all — you’re hitting a display routing problem on reboot.

Let’s pin this down cleanly.

==== On the Legion Go S + SteamOS + eGPU: ====
* The HDMI port on the eGPU is wired only to the eGPU
* On reboot, SteamOS: - Initializes the iGPU first - Sometimes fails to activate the eGPU display outputs
* Result: - Internal screen works (iGPU) - TV stays black on HDMI - eGPU may still exist, but its outputs never light up

This is a known Linux + AMD eGPU + external display-on-boot issue.

So when you say “it worked before” — yeah:
* The eGPU HDMI was being activated automatically
* A SteamOS update likely broke that behavior

==== When HDMI is black after reboot, do this on the Legion’s internal screen: ====

<syntaxhighlight lang="bash">xrandr --listproviders

</syntaxhighlight>

If you see:
* Provider 0: AMD iGPU
* Provider 1: AMD eGPU

👉 The eGPU exists, but its outputs aren’t enabled

==== ### ====

Run:

<syntaxhighlight lang="bash">xrandr --auto

</syntaxhighlight>

or more aggressively:

<syntaxhighlight lang="bash">xrandr --output HDMI-1 --auto

</syntaxhighlight>

(HDMI-1 / HDMI-A-1 may vary)

You can list outputs with:

<syntaxhighlight lang="bash">xrandr

</syntaxhighlight>

If the TV lights up → this confirms it’s a display init bug.

===== I know it sounds dumb, but: =====
* Boot with eGPU connected
* Once SteamOS is fully loaded: - Unplug HDMI from the eGPU - Plug it back in

This forces a modeset and often wakes the display.

===== SteamOS now defaults to Wayland, which is not great with AMD eGPU displays. =====

Switch to X11 in Desktop Mode:
# Desktop Mode
# Log out
# Click the ⚙️ icon on the login screen
# Select Plasma (X11) instead of Wayland
# Log back in
# Reboot with eGPU + HDMI connected

This alone fixes HDMI-on-boot for a lot of people.

===== After you get HDMI working (even temporarily): =====

<syntaxhighlight lang="bash">xrandr --output HDMI-1 --primary

</syntaxhighlight>

Then reboot.
Sometimes this “sticks” across boots.

==== Likely causes: ====
* Mesa update changed connector naming
* Kernel update changed DRM init order
* Wayland session regression
* AMD DC bug with hotplug detection

None of this is your hardware failing.

==== Just so you don’t waste time: ====
* BIOS changes ❌
* GPU priority ❌
* Reinstalling SteamOS ❌ (usually)
* Different HDMI cable (rarely helps)

==== If you want console-like reliability on TV: ====
* Use X11
* Cold boot with: - eGPU powered - HDMI already plugged in
* If black screen: - Replug HDMI once

Annoying, but stable.

==== When the TV is black after reboot: ====

👉 Does the eGPU fan spin and LED stay on?

And if you can, tell me:
* Are you in Gaming Mode or Desktop Mode when testing HDMI?
* Wayland or X11 right now?

We’re very close — this is a known, fixable Linux display-init edge case, not a dead port 🙂