bug: USB setup failure leaves DeckJoy in non-recoverable state until restart

[ioerrors]

Summary

After Start USB fails (example: Deck connected to charging dock, not a host PC), DeckJoy shows an RPC error but may not recover cleanly for retry/use/exit flows.

Example error:
joystick setup failed: rpc error: code = Internal desc = enable error no udc device found

Environment

• Device: Steam Deck OLED
• Builds tested:
  • master (v0.2.1 baseline)
  • feat/black-screen-mode branch

Observed Behavior

• Error appears after Start USB in non-host connection scenarios.
• In some runs, app does not recover to normal controller mode afterward.
• In some runs, closing DeckJoy appears to hang.
• Error text overflow/off-screen was seen on master (UI issue).

Expected Behavior

• Failed USB setup should be recoverable without restarting app.
• Retrying after connection state changes should work.
• App should always exit cleanly, even after setup failures.

Repro Steps

1. Launch DeckJoy.
2. Keep Deck connected to charging dock (no host PC for gadget mode).
3. Press Start USB.
4. Observe setup error.
5. Attempt retry and/or close app.

Suspected Areas

• deck.Run() returns after setup failure and may not restart retry path.
• Start USB may start daemon but not re-run full setup lifecycle.
• Shutdown path may depend on daemon/socket state after partial failure.

Related: #6

[Lucaber]

The "Start USB" setup should now be retryable on error. Could you please test with this release? https://github.com/Lucaber/deckjoy/releases/tag/v0.3.1

[ioerrors]

Thanks! Can confirm the retry behavior works. On v0.3.1 I'm seeing two issues with black screen: tapping doesn't restore the UI, and controller input stops working while it's active — have to kill the app to recover. Looking into it, will aim for a fix PR soon.

[ioerrors]

Thanks for the v0.3.1 update. Stability is noticeably better on my side. Even in failure modes that may be specific to my setup (and my limited understanding of the keyboard workflow), I’m no longer seeing the hard freeze / “have to restart the Deck entirely” behavior I hit before. In 0.3.1 I can at least cleanly recover via Steam menu -> Exit Game, which is a big improvement.

While testing, I think there are two distinct black-screen use cases that may be best split across SDL vs Fyne:

Keyboard/mouse workflow:

• The SDL black-screen flow seems aligned with this use case.

Controller-only workflow:

• For users who want to use the Deck purely as a controller and blank the screen (distraction/power), opening the SDL input window seems counterproductive in my testing.
• It can shift touchscreen behavior into trackpad-like mode and interfere with controller passthrough, possibly because mappings change when the SDL window becomes active.
• A Fyne-layer black screen here avoids multiple windows and avoids changing touch interpretation.

Would it make sense to support both paths?

• keep SDL black screen when entered from keyboard UI
• use a Fyne-layer black screen when entered directly from the main menu after Start USB (similar to PR feat(gui): add black screen mode #6)

That split matches my controller-first workflow much better (though I don’t know how common my workflow is). I also couldn’t reliably exit black screen mode with the current SDL-only path. I may still be missing part of the keyboard-intended desktop-mode workflow, since my use case is gaming-mode launch for controller use (for example, Cyberpunk).

Exciting related news: I also tested a one-time auth improvement. After first successful Start USB auth, subsequent Start USB runs no longer reprompt (including across restarts), which reduces friction a lot. Incoming PR on that.

Happy to open this as two small PRs if preferred:

• black-screen behavior split by entry path/use case (may depend on whether I understand the SDL / Fyne --> keyboard mode / controller mode concerns correctly, but submitting a PR for that split, up to you) fix(gui): use Fyne black screen for controller flow #10
• one-time huge auth friction reduction instead of everytime (a clean win I think~) feat(setup): install scoped one-time polkit rule #9
  test release if you want to try both of those changes together:
  https://github.com/ioerrors/deckjoy/releases/tag/ioerrors-v0.3.1-controller-auth-pack-1

[Lucaber]

#10 (comment)