iwlwifi causing system hangs on Ubuntu 19.10

Solution 1:

I'm not sure how OP finally solved it but I'm having this exact same problem. Seems to happen for a pretty specific combination of hw/sw. I have: Ubuntu 19.10 installed from scratch last week (previously had upgraded from 19.04 and so forth and maybe that's why i'm having this problem just now), with kernel 5.3.0-46-generic, Intel 9260 Wi-Fi chip in a Dell XPS 9570. Problem seems to appear if i've booted Windows before Ubuntu.

I read through the bug at https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1848921 which seems spot-on for this problem.

Short-term solution for me is the ridiculous (but working) one mentioned in the last comment: if booting after Windows, turn off the machine, disconnect power adapter and then turn on Ubuntu.

Long-term solution for me will be to upgrade to Ubuntu 20.04 (LTS) as it comes out in a couple of weeks and seems to fix this (somewhere around kernel 5.4.16).

If this is not a possibility for the reader (though in this case you should already be avoiding non-LTS releases when running Ubuntu), you may try the other solutions mentioned in the bug discussion, such as:

• Make sure Windows has Fast Boot disabled
• Manually install a different firmware for iwlwifi: download the "-34" (iwlwifi-9260-th-b0-jf-b0-34.XXXXX.X.tgz), "manually copy the contained firmware to /lib/firmware, remove all other versions and make a link to iwlwifi-9260-th-b0-jf-46.ucode that the kernel expects to load." (see bug description)
• Try configuring options in /etc/modprobe.d/wifi.conf as mentioned here
• Try a different network chip (other than 9260)
• Uprade or downgrade to a different kernel version (there are other AskUbuntu answers for this). You may already have a different one installed, in which case you can try booting to it and see if the problem persists