PXI‑5922 Fails Self-Test / Self‑Calibration in NI Hardware Configuration Utility on Ubuntu 22.04 / 24.04

Issue Details

When using a PXI‑5922 High‑Speed Digitizer in a PXI‑1090 chassis on Linux (Ubuntu 22.04 or 24.04), the module may fail self‑test or self‑calibration in NI Hardware Configuration Utility (NI HWCFG).

Observed symptoms include:

• PXI‑5922 fails Self‑Test or Self‑Calibration
• Error codes such as:
  • ‑239020

• PXI‑5922 appears partially detected, but no data or access LEDs are active
• PXI‑1090 MXI status LED changes:
  • Green → normal detection
  • Yellow → chassis not properly recognized
• PXI‑1090 chassis may not appear in NI HWCFG under certain configurations

This behavior is most commonly observed on newer Linux kernels with modern CPU security features enabled.

Solution

This issue is caused by incompatibilities between legacy PXI (PCI‑based) instruments and newer Linux security and virtualization mechanisms, including:

• IOMMU
• DMA Protection
• VT‑d (Intel Virtualization for Directed I/O)
• Modern kernel DMA handling

PXI‑5922 is a legacy PXI (PCI) device, not PXIe. While PXIe modules are generally more tolerant of modern security features, legacy PXI devices can fail when these mechanisms are active, especially on newer Linux kernels.
This is not specific to NI hardware, but rather a platform‑level limitation of PCI technology interacting with modern OS security features. To solve the issue, you can refer to the workarounds below:

1. Test Kernel IOMMU Settings by editing the GRUB configuration file:

sudo nano /etc/default/grub

Test the following kernel parameters one at a time:

• Option A: Passthrough (Recommended First Test)

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash iommu=pt"

• Option B: Fully Disable IOMMU

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash iommu=off"

Note:

• intel_iommu=off alone may not be sufficient
• iommu=off disables IOMMU globally and has shown better chassis detection in some cases

Apply Changes:

sudo update-grub
sudo reboot

After reboot, verify with:

dmesg | grep -Ei "DMAR|DMA|IOMMU"

 2. BIOS Configuration Checks (Critical)

If kernel changes are insufficient, check BIOS / UEFI settings. Naming varies by vendor.
Test these settings incrementally, rebooting between changes:

Important observations from testing:

• Disabling VT‑d or DMA Protection may cause the PXI‑1090 chassis to disappear
• Some systems force DMA Protection off when VT‑d is disabled
• The goal is to find a combination where:
  • Chassis is visible
  • PXI‑5922 passes self‑test

 3. Collect Diagnostic Logs

If the issue persists, collect and review:

lspci -v
lspci -vv
lspci -vvv

dmesg | grep -Ei "DMAR|DMA|IOMMU"
journalctl -k | grep -i IOMMU

These logs help determine whether the failure is due to:

• DMA remapping errors
• IOMMU faults
• PCI bridge / MXI issues

 4. Additional Mitigation Steps

• Test with different PXI/PXIe modules, if available, to narrow scope
• Move PXI‑5922 to another valid slot (if system allows)
• Verify Thunderbolt settings (security level, authorization)
• Test with an older kernel version (for example, Linux kernel 6.5) if supported

Additional Information

PXI‑5922 self‑test and calibration failures on Ubuntu 22.04/24.04 are typically caused by IOMMU, DMA, or virtualization conflicts introduced by modern CPUs and Linux kernels. Successful operation often requires careful tuning of kernel boot parameters and BIOS security settings.