MediaTek MT7921 Wi-Fi intermittently disappears on Ubuntu 26.04 (works on kernel 7.0.0-22 but not reliably on 7.0.0-27)

[deekshant-singhal]

Hi everyone,

I’m looking for some help with a strange Wi-Fi issue that started recently. I’m not sure if it’s related to the kernel, the driver, firmware, or possibly hardware.

Ubuntu Version

Distributor ID: Ubuntu
Description: Ubuntu 26.04 LTS
Release: 26.04
Codename: resolute

Kernel comparison:

• 7.0.0-27-generic: Intermittent Wi-Fi failures as described below.

• 7.0.0-22-generic: Switched back to this kernel and have not been able to reproduce the issue so far. Wi-Fi initializes and works normally.

Desktop Environment

Desktop: ubuntu:GNOME
Display Server: Wayland

Problem Description

I’m using an HP Pavilion 15-eg2002TU (66C03PA) with a MediaTek MT7921 802.11ax PCIe Wireless Network Adapter.

After updating to kernel 7.0.0-27, I’ve started experiencing intermittent Wi-Fi problems.

The issue is not consistent. Sometimes the laptop boots normally and Wi-Fi works perfectly. Other times:

1. Wi-Fi disappears completely.

2. The GNOME Quick Settings/network menu becomes sluggish or unresponsive, while the rest of the desktop remains mostly usable.

3. On one occasion, Brave froze and the laptop unexpectedly rebooted. After rebooting, the Wi-Fi adapter was missing.

While troubleshooting I noticed two different behaviours:

• Sometimes the wireless adapter is completely absent from the output of lspci -nnk | grep -A5 -Ei "network|wireless".

• Other times the adapter is detected normally, but the kernel reports repeated mt7921e driver/firmware timeout errors.

One thing that confused me is that simply entering the HP BIOS/Hardware Diagnostics and then booting Ubuntu again has, on a few occasions, made the Wi-Fi work normally again without changing anything.

Relevant System Information

Hardware

Laptop: HP Pavilion 15-eg2002TU (66C03PA)
CPU: Intel Core i5-1240P
RAM: 16 GB DDR4
Graphics: Intel Iris Xe
Wi-Fi: MediaTek MT7921 802.11ax PCIe Wireless Network Adapter
BIOS: F.14 (11/08/2023)
Kernel module: mt7921e

When Wi-Fi is working

lspci -nnk | grep -A5 -Ei "network|wireless"

Output:

01:00.0 Network controller [0280]: MEDIATEK Corp. MT7921 802.11ax PCIe Wireless Network Adapter [Filogic 330]
Kernel driver in use: mt7921e
Kernel modules: mt7921e

When the problem occurs

The adapter is not detected by lspci at all.

On one occasion, after logging out of my session, the following kernel messages appeared on screen. After logging back in, the Wi-Fi adapter was no longer available:

mt7921e 0000:01:00.0: driver own failed
mt7921e 0000:01:00.0: Timeout for driver own
mt7921e 0000:01:00.0: chip reset failed
mt7921e 0000:01:00.0: Message ... timeout

What I’ve Tried

• Verified that NetworkManager is running.

• Checked rfkill (nothing is blocked).

• Confirmed the required MediaTek firmware files are present.

• Checked journalctl and dmesg logs.

• Rebooted several times.

• Entered HP BIOS/Hardware Diagnostics before booting Ubuntu.

• Switched back to kernel 7.0.0-22-generic and have been using it without encountering the Wi-Fi issue. Switching back to 7.0.0-27-generic causes the issue to reappear intermittently.

Question

Has anyone experienced similar behaviour with the MediaTek MT7921 on Ubuntu 26.04?

Does this look more like:

• a known mt7921e driver issue,

• a kernel 7.0.0-27 issue,

• a firmware/BIOS problem,

• or a possible hardware issue?

If this looks like a known issue, I’d also appreciate it if someone could point me to an existing bug report or let me know if I should file one.

Thank you.

[cryorelaxo]

I have a similar problem with a USB-connected Realtek RTL88x2bu AC1200 (USB id: 0bda:b812) using the rtw88_usb driver on a HP ProDesk 400 G4 SFF on the 7.0.0-27-generic kernel.

After an hour or two, the adapter drops off my network and it refuses to authenticate entirely. I have also had to revert to 7.0.0-22-generic to get it working reliably again.

[graymech]

Have either of you updated 26.04 using software updater or the command line recently? I did today and some of the firmware modules were updated. Your particular drivers modules might be among those firmware modules ready for an update.

Regards

[deekshant-singhal]

Yes I did that too. But even in 7.0.0-22-generic version i ran into wifi disappearance error followed by fatal exception error. Although it happened only once but it still feels unreliable.

[cremfuelled]

I’ve had this same issue for a while now on my MT7922 802.11ax, even before 7.0.0-27. (Although it did get worse for some reason with that kernel) 7.2.0-rc2 seems to have fixed the issue for me. I’ve not had time to bisect the tree and see which commit fixes the issue yet though…

[cremfuelled]

I should also mention that if there is not already one reported, creating a bug report targeting the linux source package on Launchpad is the proper way to get kernel bugs tracked and fixed by the community or kernel team.