Xid 109 `CTX SWITCH TIMEOUT` on RTX 5090 / Blackwell GB202 during Forza Horizon 6 via Proton — open kernel module 595.71.05

NVIDIA Open GPU Kernel Modules Version

595.71.05 (Arch package nvidia-open-dkms 595.71.05-2).

Please confirm this issue does not happen with the proprietary driver (of the same version). This issue tracker is only for bugs specific to the open kernel driver.

• I confirm that this does not happen with the proprietary driver package.

Operating System and Version

CachyOS Linux (rolling).

Kernel Release

Linux 7.0.6-1-cachyos #1 SMP PREEMPT_DYNAMIC Mon, 11 May 2026 15:10:22 +0000 x86_64 GNU/Linux

Please confirm you are running a stable release kernel (e.g. not a -rc). We do not accept bug reports for unreleased kernels.

• I am running on a stable kernel release.

Hardware: GPU

GPU 0: NVIDIA GeForce RTX 5090 (UUID: GPU-[REDACTED-UUID])

Describe the bug

Forza Horizon 6 (Steam AppID 2483190, build 354221, run via Proton) hangs the graphics context after ~3 minutes of open-world gameplay. Every occurrence raises an Xid 109 CTX SWITCH TIMEOUT with a byte-identical signature across runs, then the game receives DXGI DEVICE_REMOVED (HRESULT 0x00000102 → WAIT_TIMEOUT) and writes a crash report.

The Xid is the first and only kernel-side fault. The user-mode crash (ACCESS_VIOLATION_WRITE while writing to a device-removed swapchain resource) is a downstream consequence, not the trigger.

Selected kernel log:

May 16 00:00:33 [REDACTED-HOST] kernel: NVRM: GPU at PCI:0000:01:00: GPU-[REDACTED-UUID]
May 16 00:00:33 [REDACTED-HOST] kernel: NVRM: Xid (PCI:0000:01:00): 109, pid=159175, name=forzahorizon6.e, channel 0x00000029, errorString CTX SWITCH TIMEOUT, Info 0x3c03f
May 16 00:05:20 [REDACTED-HOST] kernel: NVRM: Xid (PCI:0000:01:00): 109, pid=174356, name=forzahorizon6.e, channel 0x00000029, errorString CTX SWITCH TIMEOUT, Info 0x30c03f
May 16 00:42:45 [REDACTED-HOST] kernel: NVRM: Xid (PCI:0000:01:00): 109, pid=98371,  name=forzahorizon6.e, channel 0x0000001f, errorString CTX SWITCH TIMEOUT, Info 0x3c02c

(Three confirmed events across two boots — full history in attached log bundle. The channel index varies; Info always has the low byte 0x3f / 0x2c family, suggesting the same fault-class.)

The hang appears to be driver-side rather than a translation-layer artifact:

• Reproduces under both proton-cachyos-slr (custom Proton with cherry-picked vkd3d-proton commits) and stock Valve Proton (all provided by Valve which can run Forza Horizon 6 is tested; same error produced).
• VRAM usage at crash is far below budget — last run reported 4.9 GB used out of 29.0 GB budget (see attached CrashReport.xml).
• Crashes occur both with the in-game High preset and Extreme preset, with DLSS UltraPerformance through Quality, at 4K and 1440p, with/without ray tracing.
• Re-running with the very-low preset and minimum supported settings did not avoid the crash (history: prior session reproduced with Extreme + DLSS UltraPerformance at 4K, current session reproduced with High + DLSS UltraPerformance at 4K and 72 fps cap).
• No NVIDIA assert lines, no GPU-Z page-fault, no DPC watchdog trigger — the channel just stops switching context.

The pattern matches general descriptions of GSP-firmware context scheduler stalls reported elsewhere on Blackwell; this filing is intended to give NVIDIA a clean reproducer plus the requested diagnostic bundle.

To Reproduce

1. RTX 5090 / GB202 on the open kernel module 595.71.05, stable linux-cachyos 7.0.6 (Arch-based, KDE Plasma).
2. Install Forza Horizon 6 (Steam AppID 2483190).
3. Set Steam Compatibility for FH6 to proton-cachyos-11.0-20260429-slr (or stock Proton-Experimental, GE-Proton10-34, Proton 10.0 -4, etc. — both reproduce). Set launch options to PROTON_LOG="+timestamp,+seh,+loaddll" VKD3D_DEBUG=warn %command%.
4. Launch the game and reach the open world. Drive any vehicle for 3 to 5 minutes in any region.
5. The game freezes; dmesg / journalctl -k -g Xid shows Xid 109 CTX SWITCH TIMEOUT. The game writes ~/.../ForzaHorizon6/CrashReport.xml with REASON="Video card" and REASON_INFO="0x0000000000000102".
6. The system remains responsive; only the FH6 process is wedged. No reboot required.

Bug Incidence

Always

nvidia-bug-report.log.gz

nvidia-bug-report.log.gz

More Info

No response

Start by reproducing the hang with Forza Horizon 6 on the specified RTX 5090 and open module version, then inspect journalctl -k -g Xid and the attached nvidia-bug-report.log.gz. Compare the Xid 109 events and crash report across the listed Proton configurations; the investigation is complete when the context-switch failure is explained or a verified driver fix is identified.