Bug 216839

Summary:	Connecting a MT76 device causes computer to hang since linux 6.1
Product:	Drivers	Reporter:	simirmonfor
Component:	network-wireless	Assignee:	drivers_network-wireless (drivers_network-wireless)
Status:	NEW ---
Severity:	high	CC:	dev, g0000ga, gbcox, jacobecc9, kaiykay768, lorenzo.bianconi83, regressions, samuelig
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	6.1,6.1.1	Subsystem:
Regression:	Yes	Bisected commit-id:

Description simirmonfor 2022-12-23 18:49:57 UTC

I have a MediaTek Inc. MT7612U usb adapter, if it's present during boot, it will make the computer hang to the point magic key combo and switching to TTY becomes impossible, unfortunately this leaves no trace in the journal either.

This problem didn't happen on linux 5.8, 5.9 or 6, but reproduces every time with arch's build of 6.1 and 6.1.1 as well as my own build of 6.1

The system freezes before the display manager gets the chance to load if the device is connected from the start, and if connected after the boot process is complete, it will hang the system after roughly 3-4 seconds.

No errors are reported during the boot process before it freezes, and if I add "debug" to my kernel boot parameters the system won't freeze but it also didn't finish booting even after waiting for an hour, with the only thing being logged being "systemd-journald[370]: Sent WATCHDOG=1 notification." which happened roughly every 100 seconds.

Comment 1 The Linux kernel's regression tracker (Thorsten Leemhuis) 2022-12-24 05:15:20 UTC

There is a thread that discusses a similar looking issue that even has a patch that with a bit of luck will fix this for you:
https://lore.kernel.org/lkml/3cb53fbd-0bee-22f9-bba2-6ac4a87db521@nbd.name/

Comment 2 simirmonfor 2022-12-24 19:24:04 UTC

It seems it only applies on top of 6.2 so I won't be testing the patch soon.

Comment 3 Lorenzo Bianconi 2022-12-25 09:50:15 UTC

In my tests this issue is fixed by the following patch:
https://patchwork.kernel.org/project/linux-wireless/patch/20221217085624.52077-1-nbd@nbd.name/

Can you please test it?

Comment 4 Peter Lamby 2023-01-01 13:52:07 UTC

I tested the https://patchwork.kernel.org/project/linux-wireless/patch/20221217085624.52077-1-nbd@nbd.name/ patch for 6.1.1 and it fixed the freezes.

Comment 5 g0000ga 2023-01-03 14:10:00 UTC

kernels 6.1.0 to 6.1.2, issue reproduces with tplink archer t2uh. i can boot the machine, but everything freezes instantly when network manager tries to use it to connect to the network. Nothing special in the logs, i can see network interface created but no logs after that.

Comment 6 simirmonfor 2023-01-05 01:18:49 UTC

I tested 6.1.3 with https://patchwork.kernel.org/project/linux-wireless/patch/20221217085624.52077-1-nbd@nbd.name/ and there were no freezes

Comment 7 jacobecc9 2023-01-16 20:33:21 UTC

MT7610U is also broken

Comment 8 Gerald Cox 2023-01-19 17:41:32 UTC

Running Fedora 6.1.7 and issue still exists for mt76x2u, so either Fedora hasn't included this patch or it doesn't fix the issue.

Comment 9 The Linux kernel's regression tracker (Thorsten Leemhuis) 2023-01-19 20:27:28 UTC

The fix should land in master really soon now and will then with a bit of luck will then be in next weeks stable release

Comment 10 The Linux kernel's regression tracker (Thorsten Leemhuis) 2023-01-21 12:19:26 UTC

(In reply to Peter Lamby from comment #4)
> I tested the
> https://patchwork.kernel.org/project/linux-wireless/patch/20221217085624.
> 52077-1-nbd@nbd.name/ patch for 6.1.1 and it fixed the freezes.

FWIW, that patch was finally mainlined and is now queued for the next stable release with bigger changes, which likely will be released next week