Introduction
Universal Asynchronous Super Speed (UAS) is a USB protocol that improves the performance of USB devices. However, some users encounter compatibility issues with certain devices when UAS is enabled. If you're facing such an issue and wish to disable UAS for USB devices in your Linux system without knowing the specific device ID in advance, this guide will help you through the process.
Understanding the Problem
Many Linux users experience problems with USB devices due to the UAS driver, leading to system instability or device failure. This can happen particularly with older USB devices or specific external hard drives. While disabling UAS for specific devices usually requires knowing the device ID, it is possible to disable UAS globally for all USB devices by modifying GRUB settings.
The Original Code Problem Scenario
To disable UAS, the standard approach requires device IDs in the GRUB configuration. The code often looks something like this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"
However, for those who don't know their device IDs, we need a different solution.
Steps to Disable UAS Globally
Here’s how to disable UAS for all USB devices via GRUB without needing specific device IDs:
-
Open the GRUB Configuration File:
You will need to edit the GRUB configuration file. Open a terminal and type the following command to access the file with a text editor (here, we’ll use nano):
sudo nano /etc/default/grub -
Modify the GRUB Command Line:
Find the line that starts with
GRUB_CMDLINE_LINUX_DEFAULT. You will want to addusbcore.usb3=0to disable UAS support globally. The line should look like this:GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.usb3=0"Alternatively, you can also add
usbcore.old_scheme_first=1to prioritize older USB schemes which might help with compatibility. -
Update GRUB:
After making changes to the configuration file, you will need to update GRUB for the changes to take effect. Run the following command:
sudo update-grub -
Reboot Your System:
Finally, reboot your system for the changes to apply. You can do this by entering:
sudo reboot
Additional Analysis and Practical Examples
Disabling UAS may cause a decrease in performance for certain USB drives, particularly for SSDs that benefit from the UAS protocol. However, if you are experiencing issues, the stability gained by disabling UAS often outweighs the loss in speed.
Consider this scenario: You have an external hard drive that hangs or becomes unresponsive during large file transfers. By disabling UAS as described, you may find that the device operates more reliably, allowing you to transfer files without interruption.
It’s also crucial to note that if you disable UAS and find that your USB devices are still not functioning properly, consider checking for driver updates or issues specific to the devices you're using.
Useful Resources
Conclusion
Disabling UAS for USB devices on your Linux system can be accomplished through simple modifications to the GRUB configuration. This can greatly improve device compatibility and system stability, especially when dealing with older hardware or specific troublesome USB devices. By following the steps outlined in this article, you can easily manage UAS settings without needing to know specific device IDs, making your system easier to use and troubleshoot.
By understanding the UAS protocol and its implications, Linux users can take control of their device performance and ensure a smoother user experience. If you have any questions or further problems, don't hesitate to reach out to forums or communities dedicated to Linux support.
