Summary

On Ubuntu 24.04 LTS running on a laptop with an Intel Core Ultra (ILL) CPU and Intel Wi-Fi (Wi-Fi 7 class), Wi-Fi was completely unavailable even though the device was detected at the PCI level.

The issue was not missing drivers, but booting an incompatible kernel. The system was stuck booting a newer mainline kernel, while a working OEM kernel was already installed but never selected.

The issue was resolved by forcing GRUB to boot the OEM kernel (6.14) and updating GRUB.

Environment

  • OS: Ubuntu 24.04 LTS
  • Hardware: Laptop with Intel Core Ultra (ILL) CPU
  • Wi-Fi: Intel Wi-Fi (Wi-Fi 7 class, e.g. Intel Corporation Device a840)
  • Firmware: Standard linux-firmware from Ubuntu repos
  • Boot mode: UEFI (GRUB menu hidden by default)

Symptoms

GNOME Network Settings shows: “No Wi-Fi Adapter Found” Wi-Fi device is detected:

lspci | grep -i network

But driver is not bound:

sudo lshw -C network
# *-network UNCLAIMED

Investigation

The system was booting into a newer mainline kernel:

uname -r
# 6.17.0-14-generic

However, a stable OEM kernel was already present:

ls /boot | grep vmlinuz
# vmlinuz-6.14.0-37-generic
# vmlinuz-6.17.0-14-generic

Because the GRUB menu was hidden (UEFI fast boot), the system always booted into 6.17, which caused a kernel–firmware mismatch. As a result, iwlwifi failed to claim the device (UNCLAIMED).

Root Cause

  • Intel Wi-Fi drivers (iwlwifi) are highly sensitive to kernel ↔ firmware compatibility
  • Kernel 6.17 was too new for the shipped firmware
  • Kernel 6.14 (OEM) contains backported fixes suitable for this hardware
  • GRUB never selected 6.14 automatically
  • This is not a DKMS or driver installation issue.

Solution (What Fixed It)

Force GRUB to always boot the OEM kernel and update GRUB:

sudo sed -i 's/^GRUB_DEFAULT=.*/GRUB_DEFAULT="Advanced options for Ubuntu>Ubuntu, with Linux 6.14.0-37-generic"/' /etc/default/grub
sudo update-grub
sudo reboot

After reboot:

uname -r
# 6.14.0-37-generic

Then reinstall firmware:

sudo apt update
sudo apt install --reinstall linux-firmware
sudo reboot

Wi-Fi immediately became available.

After confirming stability:

sudo apt remove 'linux-image-6.17.*' 'linux-headers-6.17.*'
sudo apt autoremove
sudo update-grub

Lessons / Notes

  1. UNCLAIMED often indicates a kernel/firmware mismatch, not missing drivers
  2. On new Intel Core Ultra (ILL) systems, OEM kernels may be required
  3. Hidden GRUB menus on UEFI systems can silently lock users into a broken kernel
  4. update-grub is a critical step when dealing with kernel selection

Expected Improvement

It would be helpful if Ubuntu:

  • Preferred OEM kernels automatically on supported hardware, or
  • Warned when booting experimental/mainline kernels that break firmware compatibility

discussion