Arch Linux

Brocellous

Member

Registered: 2017-11-27

Posts: 147

iwlwifi crashes on 5.9.12+

My iwlwifi has been crashing lately with journal messages like:

$ journalctl --no-hostname -b -p3 -g iwlwifi
Dec 12 12:06:40 kernel: iwlwifi 0000:02:00.0: Error sending SCAN_CFG_CMD: time out after 2000ms.
Dec 12 12:06:40 kernel: iwlwifi 0000:02:00.0: Current CMD queue read_ptr 78 write_ptr 79
Dec 12 12:06:40 kernel: iwlwifi 0000:02:00.0: HW error, resetting before reading
Dec 12 12:06:42 kernel: iwlwifi 0000:02:00.0: Start IWL Error Log Dump:
Dec 12 12:06:42 kernel: iwlwifi 0000:02:00.0: Status: 0x00000040, count: 1809269343
Dec 12 12:06:42 kernel: iwlwifi 0000:02:00.0: Loaded firmware version: 36.ad812ee0.0 8265-36.ucode
Dec 12 12:06:42 kernel: iwlwifi 0000:02:00.0: 0x2D95A56F | ADVANCED_SYSASSERT
[...]

followed by some register dumps. I can still receive but not send traffic. I reset it by restarting iwd and systemd-networkd.

My wireless card is

$ lspci -kd::280
02:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev 78)
	Subsystem: Intel Corporation Dual Band Wireless-AC 8265
	Kernel driver in use: iwlwifi
	Kernel modules: iwlwifi

I understand that the issue here is some kind of firmware bug, but prior to last week I hadn't seen these errors. I update frequently, and after examining my pacman log linux-firmware wasn't updated very recently compared to my first recorded crash on the morning of 2020-12-08. However I did update linux:

$ awk '$4 ~ /^linux(|-firmware)$/ && $1 > "[2020-12" && $1 < "[2020-12-08"' $(pacman-conf LogFile)
[2020-12-06T11:29:02-0700] [ALPM] upgraded linux (5.9.11.arch2-1 -> 5.9.12.arch1-1)

And my kernel version at the time of the first crash was 5.9.12. Since that's the best (only) candidate I can find, I'm going to try reverting linux and see if the crashes stop.

I don't have a reliable way to reproduce the crash, so it may be a while before I can tell if it made a difference. So, my questions are:

1. The crashes so far have all happened while I had a network intense application open, i.e. a video call. Does anyone know of a startegy I could try to reliably reproduce without requiring a friend to hop in video chat with me?
2. Is it possibly caused by iwlwifi changes in 5.9.11 -> 5.9.12? I usually don't have problems between minor versions but a quick look shows there were some commits.
3. Has anyone else experienced a similar issue, or does it match a known bug?

Thanks