Public bug reported:
Summary
On Ubuntu 24.04 LTS with a current kernel, Qualcomm WCN7850 (FastConnect
7800) adapters cannot use the 5 GHz band at all. No 5 GHz APs appear in
scans, and the firmware rejects the regulatory country push at every
driver load.
The root cause is a version mismatch within 24.04: the kernel stack has
moved to 6.17+/7.x, but linux-firmware in noble still ships an
ath12k/WCN7850/hw2.0 blob built 2025-05-17. Upstream linux-firmware
carries a build from 2026-03-06 that fixes this. Copying the upstream
blobs into /lib/firmware/updates/ resolves the problem completely and
immediately.
This appears to be the same root cause as LP: #2138754, which was fixed
in linux-firmware 20250901.git993ff19b-0ubuntu1.10 — a snapshot that is
not available in noble. apt policy linux-firmware on 24.04 offers
nothing newer than the affected version, so there is no upgrade path
through the archive for LTS users.
Affected hardware
07:00.0 Network controller: Qualcomm Technologies, Inc WCN785x Wi-Fi 7(802.11be)
320MHz 2x2 [FastConnect 7800] (rev 01)
Subsystem: Foxconn International, Inc. High Band Simultaneous Wireless
Network Adapter
Kernel driver in use: ath12k_wifi7_pci
Kernel modules: ath12k
Full IDs:
07:00.0 Network controller [0280]: Qualcomm Technologies, Inc WCN785x Wi-Fi
7(802.11be) 320MHz 2x2 [FastConnect 7800] [17cb:1107] (rev 01)
Subsystem: Foxconn International, Inc. High Band Simultaneous Wireless
Network Adapter [105b:e0f7]
Kernel driver in use: ath12k_wifi7_pci
Kernel modules: ath12k_wifi7
Note this is an x86-64 AMD desktop (MSI motherboard, Foxconn NCM865 M.2
module), whereas LP: #2138754 was reported on a Lenovo Yoga Slim 7x running
qcom-x1e (ARM) kernels. The regression therefore spans both architectures and
is not specific to the Snapdragon X laptop platform.
Environment
Item Value
Ubuntu release PRETTY_NAME="Ubuntu 24.04.4 LTS"
Kernel (affected) 6.17.0-14-generic and 7.x
linux-firmware 20240318.git3b128b60-0ubuntu2.27 (latest candidate in noble)
HWE stack linux-generic-hwe-24.04:
Installed: 7.0.0-28.28~24.04.1
Candidate: 7.0.0-28.28~24.04.1
Version table:
*** 7.0.0-28.28~24.04.1 500
500 http://archive.ubuntu.com/ubuntu noble-updates/main amd64 Packages
500 http://security.ubuntu.com/ubuntu noble-security/main amd64 Packages
100 /var/lib/dpkg/status
6.8.0-31.31 500
500 http://archive.ubuntu.com/ubuntu noble/main amd64 Packages
Driver ath12k (module renamed to ath12k_wifi7_pci in 7.x)
Firmware versions
Broken — as shipped in noble's linux-firmware:
fw_version 0x1108811c fw_build_timestamp 2025-05-17 00:21
fw_build_id
QC_IMAGE_VERSION_STRING=WLAN.HMT.1.1.c5-00284.1-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
Working — current upstream linux-firmware:
fw_version 0x1103006c fw_build_timestamp 2026-03-06 09:10
fw_build_id
QC_IMAGE_VERSION_STRING=WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3
Roughly a 10-month gap, spanning a firmware branch change (c5 → c7).
Steps to reproduce
Install Ubuntu 24.04 LTS on a machine with a WCN7850 adapter.
Boot a 6.17 or newer kernel.
Ensure linux-firmware is fully up to date (20240318.…-0ubuntu2.27).
Scan for wireless networks: nmcli device wifi list
Expected result
Both 2.4 GHz and 5 GHz networks are listed. dmesg shows no regulatory
errors.
Actual result
Only 2.4 GHz networks (channels 1–13) are listed. Not a single 5 GHz AP
appears, in an area where many are known to be broadcasting and are
visible to other devices. A frequency-targeted scan is accepted but
returns zero results:
$ sudo iw dev wlp7s0 scan freq 5180 5200 5240 5745 5785 | grep -E "SSID|freq"
$ # (no output, no error)
dmesg on every driver load — reproducible via modprobe -r ath12k /
modprobe ath12k, so this is not a boot-ordering race:
ath12k_pci 0000:07:00.0: chip_id 0x2 chip_family 0x4 board_id 0xff soc_id
0x40170200
ath12k_pci 0000:07:00.0: Failed to set the requested Country regulatory setting
ath12k_pci 0000:07:00.0: Failed to set the requested Country regulatory setting
ath12k_pci 0000:07:00.0: Timeout while waiting for regulatory update
ath12k_pci 0000:07:00.0: Timeout while waiting for regulatory update
ath12k_pci 0000:07:00.0: received scan start failure event
ath12k_pci 0000:07:00.0: failed to find arvif link id 0 for frame transmission
Note that iw reg get looks healthy while the adapter is broken, which
makes this misleading to diagnose — phy#0 (self-managed) reports country
IN: DFS-FCC with all 5 GHz ranges enabled at full power, because that is
cfg80211's view. The firmware never accepted the country push and does
not agree.
SRU justification
[Impact]
WCN7850 Wi-Fi 7 users on 24.04 LTS lose the 5 GHz band entirely once
they are on a 6.17+ kernel. They are restricted to 2.4 GHz, i.e. heavy
congestion and a fraction of available throughput on hardware sold as
Wi-Fi 7. Because the LTS kernel stack rolls forward via HWE, the
affected population grows over time without any user action. There is no
fix available through the noble archive.
[Fix]
Backport the updated ath12k/WCN7850/hw2.0 firmware blobs (board-2.bin,
amss.bin, m3.bin, plus the ncm865/ variant directory) from upstream
linux-firmware into noble's linux-firmware. This is the same delta
already shipped in 20250901.git993ff19b-0ubuntu1.10 for later series
(LP: #2138754).
[Test Plan]
On affected hardware running 24.04 LTS with a 6.17+ kernel, confirm no 5 GHz
networks appear in nmcli device wifi list and that the regulatory errors above
are present in dmesg.
Install the proposed linux-firmware.
Reboot.
Confirm dmesg | grep -i ath12k shows a newer fw_build_timestamp and no Failed
to set the requested Country regulatory setting or Timeout while waiting for
regulatory update lines.
Confirm 5 GHz networks are listed and a connection can be established.
Verified locally: placing the current upstream blobs in
/lib/firmware/updates/ath12k/WCN7850/hw2.0/ and rebooting fixes the
issue completely. All regulatory errors disappear and 5 GHz works
normally.
[Where problems could occur]
The change is confined to firmware blobs for a single chipset, so
regression risk is limited to WCN7850/WCN785x users. A bad firmware bump
could affect 2.4 GHz operation, 6 GHz availability, or introduce
initialisation failures on board variants other than the one tested
here. Testing across several WCN7850 modules (NCM865 and the Snapdragon
X laptop variants) is advisable, since board_id reads back as 0xff on
this module and board-data selection falls back to a default entry.
[Other Info]
Workaround for affected users, pending an SRU — this survives package
upgrades because dpkg never writes to /lib/firmware/updates/, which the
kernel firmware loader searches first:
bash
git clone --filter=blob:none --sparse --depth 1 \
https://gitlab.com/kernel-firmware/linux-firmware.git /tmp/lfw
git -C /tmp/lfw sparse-checkout set ath12k/WCN7850
sudo mkdir -p /lib/firmware/updates/ath12k/WCN7850/hw2.0
sudo cp -r /tmp/lfw/ath12k/WCN7850/hw2.0/* \
/lib/firmware/updates/ath12k/WCN7850/hw2.0/
sudo update-initramfs -u -k all
sudo reboot
Related reports:
LP: #2138754 — ath12k wcn7850 5 GHz broken in kernel 6.17+ (fixed in later
series)
LP: #2130490 — ath12k: DFS-UNSET disables some channels of 5 GHz
LP: #2080428 — Updating firmware disabled QCOM WiFi WCN7850 on T14 Gen5 AMD
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-firmware 20240318.git3b128b60-0ubuntu2.27
ProcVersionSignature: Ubuntu 7.0.0-28.28~24.04.1-generic 7.0.12
Uname: Linux 7.0.0-28-generic x86_64
ApportVersion: 2.28.2-0ubuntu0.1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: karan 2565 F.... wireplumber
/dev/snd/controlC0: karan 2565 F.... wireplumber
/dev/snd/controlC2: karan 2565 F.... wireplumber
/dev/snd/seq: karan 2559 F.... pipewire
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Sun Aug 2 02:23:53 2026
Dependencies: firmware-sof-signed 2023.12.1-1ubuntu1.11
InstallationDate: Installed on 2026-08-01 (0 days ago)
InstallationMedia: Ubuntu 24.04.4 LTS "Noble Numbat" - Release amd64 (20260210)
MachineType: Micro-Star International Co., Ltd. MS-7E62
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 nvidia-drmdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-28-generic
root=UUID=cd31959d-bf5a-4696-8121-41d3b50808d0 ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-7.0.0-28-generic N/A
linux-backports-modules-7.0.0-28-generic N/A
linux-firmware 20240318.git3b128b60-0ubuntu2.27
SourcePackage: linux-firmware
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/19/2026
dmi.bios.release: 5.41
dmi.bios.vendor: American Megatrends International, LLC.
dmi.bios.version: 2.A60
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: MAG B850 TOMAHAWK MAX WIFI (MS-7E62)
dmi.board.vendor: Micro-Star International Co., Ltd.
dmi.board.version: 2.0
dmi.chassis.asset.tag: To be filled by O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Micro-Star International Co., Ltd.
dmi.chassis.version: 2.0
dmi.modalias:
dmi:bvnAmericanMegatrendsInternational,LLC.:bvr2.A60:bd05/19/2026:br5.41:svnMicro-StarInternationalCo.,Ltd.:pnMS-7E62:pvr2.0:rvnMicro-StarInternationalCo.,Ltd.:rnMAGB850TOMAHAWKMAXWIFI(MS-7E62):rvr2.0:cvnMicro-StarInternationalCo.,Ltd.:ct3:cvr2.0:skuTobefilledbyO.E.M.:pfaTobefilledbyO.E.M.:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: MS-7E62
dmi.product.sku: To be filled by O.E.M.
dmi.product.version: 2.0
dmi.sys.vendor: Micro-Star International Co., Ltd.
** Affects: linux-firmware (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug ath12k noble regression wcn7850
** Attachment added: "dmesg.txt"
https://bugs.launchpad.net/bugs/2162643/+attachment/5988556/+files/dmesg.txt
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https://bugs.launchpad.net/bugs/2162643
Title:
[SRU] ath12k WCN7850: 5 GHz non-functional on 24.04 LTS — packaged
linux-firmware predates upstream regulatory fix
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