Ubuntu freezes when AC 430 WiFi Dongle is plugged in

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1824650

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

Would it be possible for you to test the latest upstream kernel? Refer
to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest
v5.1-rc4 kernel [0].

If this bug is fixed in the mainline kernel, please add the following
tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag:
'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as
"Confirmed”, and attach dmesg.

Thanks in advance.

[0] https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.1-rc4/

apport information

apport information

Please attach full dmesg under v5.1-rc4.

Does kernel parameter mt76x0u.disable_usb_sg=1 help for v5.1-rc4?

I've modified the /etc/sysctl.conf with

mt76x0u.disable_usb_sg=1

but the error still appears.

What's the output of `cat /sys/module/mt76x0u/parameters/disable_usb_sg`?

The AC860 seems to suffer from the same problem.

Here is the output of 'cat: /sys/module/mt76x0u/parameters/disable_usb_sg'

cat: /sys/module/mt76x0u/parameters/disable_usb_sg: No such file or directory

It seems the only directory where the module is located is /lib/modules/x.xx.x-xxxxxx-lowlatency/kernel/drivers/net/wireless/mediatek/mt76/...

Please use /etc/modprobe.d or kernel parameter instead of sysctl.conf.

I've created a wireless.conf in the /etc/modprobe.d directory with the following line: 'mt76x0u.disable_usb_sg=1'.

Now the AC430 is booting right into Dongle-mode instead of USB-Storage-mode, but the error still appears.

Should be "options mt76x0u disable_usb_sg=1".

I've replaced the line "mt76x0u.disable_usb_sg=1" with "options mt76x0u disable_usb_sg=1" and did a reboot, same result. The AC430 is booting right into Dongle-mode instead of USB-Storage-mode, but the error still appears.

Sorry for the belated response.

There are some of new fixes in latest mainline kernel. Can you test it again?

Hello Kai-Heng Feng!

The upgrade to the mainline kernel ver. 5.3rc3 fixed the problem, now it's working OOTB! Thank you everyone for your hints and support!

Hello Rico,
does the stick still work with newer mainline kernels?
Or have you even managed to use it with newer Ubuntu kernels?

Hello Robert,

Please excuse my late reply. I now have the Ubuntu Studio version 20.04.3 LTS (Kernel 5.4) and the error unfortunately occurs again. But I found out something interesting: If you "cold boot" Ubuntu Studio with the WiFi adapter plugged in, the "dmesg error" flooding occurs and the system freezes. But if you start Windows before and then reboot into Ubuntu Studio, the stick is mounted as WiFi adapter and usable without errors.

Thank you for your update, Rico!
Unfortunately, this workaround is costly in time, disk space, and psychologically ;-)

Hello everyone,

I'll add the DMESG file so you can see how the dongle should ideally be loaded. I also saw in the boot log of Windows that the driver fwlanusb6 is addressed, maybe this information is helpful for troubleshooting..

It seems to me that the stick checks if the operating system is Windows. If it is, it grants access to the EEPROM of the stick. If the operating system is not Windows, EEPROM access is denied. This could also explain why it only works for a restart, but not for a "cold start". However, it may just be a guess.