NI Linux Device Drivers 2021 Q3 Known Issues

Overview

This document contains the NI Linux Device Drivers known issues that were discovered before and since the release of NI Linux Device Drivers 2021 Q3. Known issues are performance issues or technical bugs that NI has acknowledged exist within this version of the product.

 

Not every issue known to NI appears on this list; it is intended to show the most severe and common issues that you may encounter and provide workarounds when possible. Other technical issues that you may encounter could occur through normal product use or system compatibility issues. You may find more information on these issues in NI’s Product Documentation, Knowledgebase, or Community.

Bug Number

Legacy ID

Description

Details

1448861, 1482726, 1482726

System Crashes When NI Drivers Exceed the Default Max for iNotify Instances

When running code that initializes NI drivers, the system crashes. This may be because the NI drivers have requested more than the 128 iNotify instances that the default Linux kernel allows. The likelihood of encountering this issue increases as the number of installed drivers increases.

Workaround:

Increase the iNotify limit from the default 128 to a larger number, such as 12288.

You can increase the iNotify limit permanently through the following:
  1. Add      
    fs.inotify.max_user_instances=<Upper Limit> to /etc/sysctl.conf 
  2. Run      
    sysctl -p 
    to reload the limit
     

  3. Run      
    sysctl -a | grep fs.inotify.max_user_instances 
    to see that the new limit is set.


Or you can increase the iNotify limit after every restart with this command:

sudo sysctl -w fs.inotify.max_user_instances=<Upper Limit>
Note: <Upper Limit> can be any large number such as 12288.

Reported Version:

NI Linux Device Drivers: 2021 Q3

Resolved Version:

N/A

Added:

Aug 10, 2021

2407595, 2410935

Linux PC restarts after reprogramming the FPGA on a PXI device

When reprogramming the FPGA of some models FlexRIO, or other user-programmable FPGA cards with a custom bitfile, the system crashes. When the system restarts, the FPGA appears to have the intended FPGA on it.

This is known to occur on non-PXI host PCs running Linux that have a MXIe connection to a PXI chassis where the FPGA card is located. It stems from differences in how the host PC OS and BIOS treat the PCI bus interruption that occurs when certain customizable FPGA cards load a new bit file. The new bit file will successfully load, however it will cause a system crash.

If a given hardware configuration is affected (Host PC, MXIe card, PXI chassis, and PXI slot), the crash will occur every time a new bit file is downloaded.

Workaround:

There is no known universal workaround because there are many factors involved in how the system treats PCI interrupts. However, if the BIOS has an option to enable "PCIe Hotplug and PCIe ACPI Hot Plug" that is likely to solve the problem. In addition, changing any of the configuration can make a difference including the Host PC model, MXIe model, PXI chassis model, and FPGA card slot number.

Reported Version:

NI Linux Device Drivers: 2021 Q3

Resolved Version:

N/A

Added:

Jul 21, 2023

Final Time Issue Listed

Issues found in this section will not be listed in future known issues documents for this product.

There are currently no issues to list.

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Glossary of Terms

 

  • Bug ID - When an issue is reported to NI, you may be given this ID or find it on ni.com.  You may also find IDs posted by NI on the discussion forums or in KnowledgeBase articles.
  • Legacy ID – An older issue ID that refers to the same issue.  You may instead find this issue ID in older known issues documents.
  • Description - A few sentences which describe the problem. The brief description given does not necessarily describe the problem in full detail.
  • Workaround - Possible ways to work around the problem.
  • Reported Version - The earliest version in which the issue was reported.
  • Resolved Version - Version in which the issue was resolved or was no longer applicable. "N/A" indicates that the issue has not been resolved.
  • Date Added - The date the issue was added to the document (not the reported date).