Enable CONFIG_RTW89_8852AU (RTL8852AU/8832AU USB Wi-Fi 6)

[kleinc80]

Describe the bug

The mainline rtw89 driver gained USB support for the RTL8852AU in 6.19 (CONFIG_RTW89_8852AU, e.g. TP-Link Archer TX35U). The Kconfig entry is present in rpi-6.19.y and later, but the option is not set in bcm2711_defconfig, bcm2711_rt_defconfig or bcm2712_defconfig, while RTW89_8851BU and RTW89_8852BU already are (#7096).

Could it be enabled as CONFIG_RTW89_8852AU=m? And would a backport to rpi-6.18.y be feasible, as seems to have been done for 8852BU? Currently the only option on Pi OS is an out-of-tree DKMS driver.

Device: Raspberry Pi 4B, 6.12.109+rpt-rpi-v8 (an upgrade to trixie/6.18 is planned), adapter USB ID 3625:010f (Realtek 802.11ax WLAN Adapter - 3625:010f is already in the mainline rtw8852au.c device table, so enabling the option should be sufficient for this adapter).

Steps to reproduce the behaviour

Any clean install of Pi OS

Device (s)

Raspberry Pi 4 Mod. B

System

Raspberry Pi 4 Model B Rev 1.1
PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"
NAME="Debian GNU/Linux"
VERSION_ID="12"
VERSION="12 (bookworm)"

Raspberry Pi reference 2024-03-15
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, f19ee211ddafcae300827f953d143de92a5c6624, stage2

Linux raspberrypi 6.12.109+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.109-1+rpt1 (2026-09-11) aarch64 GNU/Linux
Revision : c03111
Model : Raspberry Pi 4 Model B Rev 1.1
Throttled flag : throttled=0x0
Camera : supported=0 detected=0, libcamera interfaces=0

USB Information

/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
|__ Port 1: Dev 2, If 0, Class=Vendor Specific Class, Driver=rtw89_8852au_git, 5000M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 4, If 0, Class=Vendor Specific Class, Driver=ftdi_sio, 12M
|__ Port 4: Dev 5, If 0, Class=Mass Storage, Driver=uas, 480M

Logs

No response

Additional context

No response

[pelwell]

You appear to be running a 6.12 kernel, and we're currently shipping 6.18, but (as you said) the driver only appeared in 6.19. There are four commits that make up the driver in 6.19:

0029ccab53acc wifi: rtw89: Add rtw8852au.c
a2f1fc9ab6fb0 wifi: rtw89: 8852au: add support for TP TX30U Plus
292c0bc8acb68 wifi: rtw89: Add support for D-Link VR Air Bridge (DWA-F18)
623c177323ec1 wifi: rtw89: Enable the new rtw89_8852au module

I'm prepared to backport them to 6.18 - they apply cleanly - and add the extra config setting. As that what you had in mind?

[kleinc80]

Hi @pelwell, Thanks for the quick reply! That is exactly what I have in mind! I'll upgrade to trixie / 6.18 kernel soon and that's why.

The linked issue #7647 is interesting: I think, we also need commit 80119a77e5b0 on top of the commits mentioned by you if we want to use the adapter in access point mode - agree? That seems to be handled via PR #7648 though.

[pelwell]

I spoke too soon - although the commits apply, they don't build as is on 6.18 due to other changes. I'll see how painful its actually going to be, but I'm not promising anything.

[kleinc80]

No worries! I think the drivers would be a cool addition to the current kernel but it's not like we're talking about a critical bug here.

[pelwell]

That wasn't too bad - just three more commits. See #7649.

If you wait about 25 minutes you'll be able to install a trial 6.18 build including the new driver, but read the caveats first.

[kleinc80]

Amazing! I never expected this to happen that fast.

I'll not try to run my bookworm with the 6.18 kernel but install a fresh trixie first - and then the risk of breaking something is irrelevant anyways.