Ubuntu freezes when AC 430 WiFi Dongle is plugged in

[Rico Heartstrings]

Ubuntu crashes after a short time after plugging in the WiFi stick "AC430". The kernel fails to load the driver and the following message appears repeatedly:

[ 800.177462] mt76x0u 1-1.1.3.2:1.0: rx urb failed: -32
[ 800.177711] mt76x0u 1-1.1.3.2:1.0: rx urb failed: -32
[ 800.177961] mt76x0u 1-1.1.3.2:1.0: rx urb failed: -32
[ 800.178211] mt76x0u 1-1.1.3.2:1.0: rx urb failed: -32
[ 800.178461] mt76x0u 1-1.1.3.2:1.0: rx urb failed: -32
[ 800.178712] mt76x0u 1-1.1.3.2:1.0: rx urb failed: -32
[ 800.181962] mt76x0u 1-1.1.3.2:1.0: rx urb failed: -32
...

Tested with Kernel 4.19 and 5.0 (5.0.2)
Tested with the following distributions:
Ubuntu Cosmic Cuttlefish 18.10
Ubuntu Studio 18.10
Ubuntu Disco Dingo 19.04

40-usb_modeswitch.rules was already modified to load the driver, otherwise the system chooses Driver=option.
---
ProblemType: Bug
ApportVersion: 2.20.10-0ubuntu13.2
Architecture: amd64
CurrentDesktop: XFCE
DistroRelease: Ubuntu 18.10
InstallationDate: Installed on 2019-03-31 (13 days ago)
InstallationMedia: Ubuntu-Studio 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.2)
NonfreeKernelModules: nvidia_modeset nvidia
Package: linux (not installed)
Tags: cosmic
Uname: Linux 5.0.2-050002-lowlatency x86_64
UnreportableReason: The running kernel is not an Ubuntu kernel
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm audio cdrom dialout dip fax floppy lpadmin plugdev sambashare scanner sudo tape vboxusers video
_MarkForUpload: True

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

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.

[Kai-Heng Feng (kaihengfeng)]

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/

[Rico Heartstrings (blazegriff1n)]

apport information

[Rico Heartstrings (blazegriff1n)]

apport information

[Kai-Heng Feng (kaihengfeng)]

Please attach full dmesg under v5.1-rc4.

[Kai-Heng Feng (kaihengfeng)]

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

[Rico Heartstrings (blazegriff1n)]

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

mt76x0u.disable_usb_sg=1

but the error still appears.

[Kai-Heng Feng (kaihengfeng)]

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

[karmen (blue-t)]

The AC860 seems to suffer from the same problem.

[Rico Heartstrings (blazegriff1n)]

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/...

[Kai-Heng Feng (kaihengfeng)]

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

[Rico Heartstrings (blazegriff1n)]

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.

[Kai-Heng Feng (kaihengfeng)]

Should be "options mt76x0u disable_usb_sg=1".

[Rico Heartstrings (blazegriff1n)]

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.

[Kai-Heng Feng (kaihengfeng)]

Sorry for the belated response.

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

[Rico Heartstrings (blazegriff1n)]

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!

[Robert Pollak (robert-pollak)]

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

[Rico Heartstrings (blazegriff1n)]

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.

[Robert Pollak (robert-pollak)]

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

[Rico Heartstrings (blazegriff1n)]

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.