WIFI disconnect on Jetson Thor - random disconnect

Robotics & Edge Computing Jetson Systems Jetson Thor
1

🛑 Jetson Thor (JetPack 7 / Ubuntu 24.04) – RTL8852CE WiFi crashes

Platform

Component Value
Board Jetson Thor
JetPack 7 (L4T R36 / R38, Ubuntu 24.04)
WiFi Realtek RTL8852CE (PCIe, 802.11ax)
Kernel 6.8.12-tegra
Driver rtl8852ce v1.19.16_nv-126-10-g6784793e9 (NVIDIA-certified)

❗ Symptoms

After random uptime (minutes → hours) WiFi becomes completely unusable:

  • Endless reconnect loops
  • Association request to the driver failed
  • CTRL-EVENT-ASSOC-REJECT status_code=8
  • Eventually the interface becomes permanently broken until reboot

🧨 Kernel errors at failure

The failure is always preceded by IOMMU queue collapse:

arm-smmu-v3 ... EVTQ overflow detected -- events lost

Immediately followed by RTL8852CE reconnect storms and wpa_supplicant failures.

🔧 Mitigations already applied (no effect)

PCIe / Power Management

  • PCIe ASPM fully disabled

pcie_aspm=off


* Runtime PM disabled on device

* ```
/sys/bus/pci/devices/.../power/control = on

Realtek driver power saving fully disabled

options rtw8852ce disable_aspm=1
options rtw8852ce disable_lps_deep=1
options rtw8852ce power_save=0
options rtw8852ce ips=0

Userspace

  • NetworkManager WiFi powersave disabled
  • Udev rules forcing PCI power to on

➡️ Issue still reproduces reliably after several hours.

🧠 Strong indicators

  • Failures are tightly correlated with ARM SMMU EVTQ overflow
  • RTL8852CE appears to leak or spam DMA faults
  • SMMU event queue eventually overflows → device becomes unrecoverable
  • Only a full reboot restores WiFi

This strongly points to a DMA/IOMMU bug in the RTL8852CE driver on Thor (T264).

📦 System / L4T version

# R38 (release), REVISION: 2.2, GCID: 42205042, BOARD: generic, EABI: aarch64
# DATE: Thu Sep 25 22:47:11 UTC 2025
# KERNEL_VARIANT: oot

TARGET_USERSPACE_LIB_DIR=nvidia
TARGET_USERSPACE_LIB_DIR_PATH=usr/lib/aarch64-linux-gnu/nvidia
nvidia-l4t-core 38.2.2-20250925153837

❓ Request to NVIDIA

  • Is RTL8852CE known to have SMMU / DMA issues on Thor (T264)?
  • Is there a newer driver drop or kernel patch that fixes EVTQ overflow?
  • Is an IOMMU passthrough / non-translated mode recommended for WiFi on Thor?

This currently makes Jetson Thor unsuitable for long-running headless deployments. If no reply until 05th Jan 2026 - the device must be returned to store.

2

You might find some of the information in this post helpful.

3

Thank you for the link - I already saw this - but fixes it only for some time - the interval got longer but still breaks after several hours, esp. when Thor is running without load.

4

There are hints that this causes instability on Thor - can NVIDIA confirm this and have a passthrough solution?

6

There is no update from you for a period, assuming this is not an issue anymore.
Hence, we are closing this topic. If need further support, please open a new one.
Thanks ~0121

Hi,
Do you see any error message in dmesg? Please attach dmesg log(from booting) for reference.