# Ubuntu – System with Intel wireless AC-9462 freezes unless WiFi is diabled due to missing firmware

driverskernelnetworkingwireless

I have NUC 7PJYH with Intel wireless AC-9462 card. The problem is that systems randomly freezes when using WiFi. There are no freezes when wifi is disabled. I tried to use different kernels, but still the same behaviour.

I investigated dmesg when I was on kernel 4.16.12 and I found that the kernel is asking for iwlwifi-9000-pu-b0-jf-b0-35 and iwlwifi-9000-pu-b0-jf-b0-36 firmware files. I tried to find these files on wireless.wiki.kernel.org. I went through all repositories they maintain and I found only versions 34 and 38 of this firmware.

Where can I find the correct firmware for kernel 4.16? These files are not even in the official linux-firmware package tree.

EDIT:

wifi related dmesg output:

[    3.476177] iwlwifi 0000:00:0c.0: enabling device (0000 -> 0002)

[    3.483822] iwlwifi 0000:00:0c.0: Direct firmware load for iwlwifi-9000-pu-b0-jf-b0-36.ucode failed with error -2

[    3.483839] iwlwifi 0000:00:0c.0: Direct firmware load for iwlwifi-9000-pu-b0-jf-b0-35.ucode failed with error -2

[    3.497077] iwlwifi 0000:00:0c.0: loaded firmware version 34.3125811985.0 op_mode iwlmvm

[    3.570636] iwlwifi 0000:00:0c.0: Detected Intel(R) Dual Band Wireless AC 9462, REV=0x318

[    3.624572] iwlwifi 0000:00:0c.0: base HW address: 68:ec:c5:9c:38:3f

[    3.685419] ieee80211 phy0: Selected rate control algorithm 'iwl-mvm-rs'

[    3.974259] iwlwifi 0000:00:0c.0 wlo1: renamed from wlan0

[    4.856976] iwlwifi 0000:00:0c.0: Conflict between TLV & NVM regarding enabling LAR (TLV = enabled NVM =disabled)


• I believe that the reason that you nor I can find any x.35 or x.36 firmware with a thorough web search is that they don't yet exist. The driver in question, iwlwifi, is written to look for the latest firmware version first; failing to find it, look for the next latest and so on until a suitable firmware file is found.

At the same time, the driver is written to automatically use later firmware versions as they are developed and included in newer versions of linux-firmware. In other words, when x.35 is written and released, the driver iwlwifi will find and use it without the necessity of a newer version of the driver. This is quite common in Intel and some other wireless drivers.

I think there is some reason other than firmware that causes your system to hang when using wireless. I invite you to ask a new open-ended question and include: dmesg | grep -e iwl -e wlp.

EDIT: We see this clue in your dmesg:

Conflict between TLV & NVM regarding enabling LAR (TLV = enabled NVM =disabled)

I suggested that you try a driver parameter:

sudo modprobe -r iwlwifi && sudo modprobe iwlwifi lar_disable=Y


It seems to have solved the hang issue so I suggest that you make it permanent:

sudo -i
echo "options iwlwifi lar_disable=Y"  >>  /etc/modprobe.d/iwlwifi.conf
exit


You should be all set.