RTX 5070 (GB205): Xid 32 → Xid 56 → "Wait for channel idle timed out" → full hard-freeze under sustained display+compute load — 595.71.05 open module, X11, Resizable BAR enabled

Summary

On an RTX 5070 (GB205) running the 595.71.05 open kernel modules on X11, the GPU's display path intermittently faults with NVRM Xid 32 and/or Xid 56 originating from desktop graphics clients (browser, gnome-shell). On 2026-06-04 the fault escalated into a complete, unrecoverable system freeze requiring a hard power-cycle (no clean shutdown, no kernel oops). The compute path (CUDA, via Ollama) was active throughout and never faulted.

This appears to be the same display-engine instability class as forum thread 365287 and issues #1132 / #1134, but with a different configuration and trigger that none of those cover:

• vs. #1132 / #1134: those are Resizable BAR disabled / BAR1 undersized (__nv_drm_gem_nvkms_map range crossing the BAR1↔BAR3 boundary). Here Resizable BAR is enabled (BAR1 = 16 GiB), so the BAR-overflow mechanism does not apply.
• vs. forum 365287: identical symptom cascade and an identical Xid 56, CMDre 00000007 fingerprint, but that report's root cause was GPU state lost across an S3 resume with nvidia-suspend/nvidia-resume disabled. Here those services are enabled and no suspend/resume occurred before the crash — the machine was awake under continuous load.

Environment

Symptom / cascade

The GPU drives both the desktop and a CUDA compute workload (Ollama). All faults originate from display/graphics clients; the compute workload never appears in any Xid.

Event A — 2026-06-04 — fatal (hard freeze)

09:33:49  kernel: NVRM: Xid (PCI:0000:01:00): 32, pid=13307, name=brave, channel 0x00000004 intr0 00040000
09:33:49  kernel: NVRM: Xid (PCI:0000:01:00): 32, pid=13307, name=brave, channel 0x00000004 intr0 00040000
09:33:50  brave: ERROR ...shared_context_state.cc:1317] SharedContextState context lost via EXT_robustness.
                 Reset status = GL_GUILTY_CONTEXT_RESET_KHR
09:33:50  brave: GPU process exited unexpectedly: exit_code=8704
          ... ~6 min of normal operation ...
09:39:59  kernel: NVRM: Xid (PCI:0000:01:00): 32, pid=9397, name=gnome-shell, channel 0x00000007 intr 02000000
09:40:04  gdm-x-session: (WW) NVIDIA: Wait for channel idle timed out.
09:40:11  gdm-x-session: (WW) NVIDIA: Wait for channel idle timed out.
09:40:52  <last log line; machine frozen — required hard power-cycle>

The first Xid 32 (browser channel) was survivable — Chromium reset its GPU context and continued. The second Xid 32, on gnome-shell's channel, was not: the X driver then blocked on "Wait for channel idle timed out" and the entire machine became unresponsive within ~50 s. The system journal ends mid-stream with no shutdown sequence, and /proc/sys/kernel/tainted shows only out-of-tree+unsigned module bits (no TAINT_DIE) — i.e. a hard hang, not a logged panic.

Event B — 2026-06-01 — non-fatal (recovered), same week

09:54:19  kernel: NVRM: Xid (PCI:0000:01:00): 56, CMDre 00000007 00000404 ffffffff 00000004 00800000
09:54:19  kernel: NVRM: Xid (PCI:0000:01:00): 56, CMDre 00000007 00000000 00000000 00000001 00800000
09:54:24  gdm-x-session: (WW) NVIDIA: Wait for channel idle timed out.

Here the display engine threw Xid 56 (the CMDre 00000007 fingerprint matches forum 365287's fatal event exactly) plus the same channel-idle timeout, but the X driver recovered and the session stayed up. This suggests the same underlying display-engine fault can either recover (Xid 56, Event B) or wedge the whole machine (Xid 32 on the compositor channel, Event A).

Ruled out

• S3 suspend/resume corruption (the 365287 root cause): nvidia-suspend/resume/hibernate are enabled and no suspend occurred before the crash — uptime was continuous under load.
• Thermal / power: no HW/SW thermal or power-brake slowdown; idle/light temps (~58 °C), 39 W of 250 W.
• CPU MCE: none.
• OOM: no oom-killer events.
• PCIe: no AER / corrected errors / link drops for 0000:01:00.
• VRAM/ECC: consumer card (ECC N/A); no remapped rows / channel-repair pending.
• Kernel panic: none recorded (taint = out-of-tree+unsigned module only).

What seems to trigger it

Sustained mixed load: the 5070 simultaneously drives an X11 desktop with many GPU-accelerated clients (Chromium-based browser, gnome-shell, Electron apps) and a continuous CUDA workload (Ollama embeddings). Faults appear under this concurrency without any suspend, gaming/Proton, or BAR-undersize condition.

Request

• Confirm whether the Xid 32 → Xid 56 (CMDre 00000007) → channel-idle timeout display-engine failure on GB205 / 595.71.05 is tracked, and whether it is distinct from the BAR-undersize (#1132/#1134) and S3-resume (forum 365287) cases given Resizable BAR is enabled and no suspend is involved here.
• Guidance on diagnostics to capture next time it degrades (the freeze is total, so nvidia-bug-report.sh can't run post-hang — happy to capture it live at first Xid if there's a recommended trigger).

I can attach a full nvidia-bug-report.sh log and complete journalctl -b -1 from the crashed boot on request.

Start with the Xid 32, Xid 56, and channel-idle timeout logs in this report, comparing Event A and Event B with issues #1132/#1134 and forum thread 365287. Capture nvidia-bug-report.sh output live at the first Xid if possible, and use the requested diagnostics to determine whether this is a distinct tracked failure mode.