Support for Asus ZenWiFi BT8 Tri-band Wifi7 (Mediatek MT7988)

Edit:

Bloddy hell, it was able to do it. For the time being its sort of a multi-irq lite, but its real.

root@OPENWRT-SALON:~# cat /proc/interrupts | grep mt7996
101: 85618 0 0 GICv3 237 Level mt7996e
102: 0 0 0 GICv3 238 Level mt7996e-hif
130: 73828 0 0 MSI 524288 Edge mt7996e-aux
root@OPENWRT-SALON:~#

PS : I tried to get the LLMs to split the wifi interface irqs but again they were not able to do so… I got opus 4.7 giving it a shot now… will report back how it goes.

@anom3 , where can we find the build/code? here somewhere? https://github.com/anom3

Hello everyone. I recently purchased this router to replace my RT-AX59. I've encountered very poor performance in Wi-Fi signal repeater mode (I'm not sure what that's called).

My friend has a router, but it's not an OpenWRT. It's connected to a provider cable and distributes internet via Wi-Fi, as usual. I have my own router, configured for a Wi-Fi connection in client mode, and on the same interface, I have Wi-Fi configured in master mode for my network. I can't use repeater mode because my network needs to have a different name/password/ip-addresses. Everything works on the 5GHz band for maximum speed and a good signal. My friend's router only supports Wi-Fi 5 (AC), AX59 works in AX.

So here's the main problem: my old RT-AX59 router handles this perfectly (it's running firmware 25.12.2), delivering 150 Mbps internet speed (considering my friend's wired data plan is 300 Mbps). But on the BT8, the speed is catastrophically low, around 20 Mbps. Under exactly the same settings and conditions. I tried building both the snapshot version 34006 and the stable 25.12.1/25.12.2 – both showed the same low speed behavior.

I tried changing the channel width from 20/40 MHz, different channels, and setting the BE/AX/AC modes —nothing helps. I'm still getting the same pathetic 20 Mbps internet speed.

Google AI told me it's due to imperfect MediaTek MT7988 drivers in OpenWRT. I'm not sure that the stock firmware for the BT8 from Asus will handle this configuration (Wi-Fi client + Wi-Fi master), and I sometimes need to run OpenConnect VPN to access the office network, which AsusWRT definitely can't do (i know about ASUSWRT-Merlin, but it doesn't support BT8 yet). Any suggestions?

You would be better served by posting this as a separate thread since this looks like a general config issue, not a BT8 issue.

Hi everyone. I picked up this router on sale and I'm wondering how the performance is for openwrt before I decide to keep it or not. What are the current limitations and how stable is it? I plan on using a pair of them as WiFi access points behind a router, so mostly focused on wifi, but would be good to also know the router limitations. Thank you!

Performance is the same as other filogic 860/880 devices. Very stable; no crashes at all.

Wifi7 limitations for all manufacturer's routers:

  • eMLMR MLO is busted and will likely never be fixed.
  • Wifi7 client compatibility and incompatibility issues.

Hello everyone. Has anyone tried to enable WED on MT7988 yet ? In the mtk_wed_mcu.c code, I saw that there is code to load MT7988_FIRMWARE_WO0 and MT7988_FIRMWARE_WO1, but there is another WO2 found in the original firmware, so I think the WED offloading code for MT7988 is still missing the loading of the WO2 firmware.

agreed, I'm permanently running SNAPSHOT from https://downloads.openwrt.org/releases/25.12-SNAPSHOT/ at present until the situation improves.

WED should work if you adapt from previous asus models:
e.g.
(https://openwrt.org/toh/asus/tuf-ax6000#wireless_ethernet_dispatch_wed_hw_acceleration_for_wireless_clients)

Enable WED:

* Edit `/etc/modules.conf` and append this line: `options mt7996e wed_enable=Y`
* This change requires a reboot

$ cat /sys/module/mt7996e/parameters/wed_enable 
Y

Beamforming and BSS coloring should also work if adapted over.

BT8 has dropped to $198 amazon USA; $198 Asus USA webshop. Discounts may be happening in other countries as well.

What is eMLMR MLO? You're saying this will never be fixed?

Other than that, is MLO working in OpenWRT? Besides the two problems that you mentioned, is the BT8 working reliably as a WiFi 7 router or even access point?

(https://www.rtings.com/router/learn/research/wifi-7-mlo)

eMLMR is broken on all manufacturers; "Rel 2" hardware changes required.

Openwrt is stable with no crashes on the BT8.

Mine is running as barely more than an AP inside an otherwise Mikrotik Network and it's pretty damn solid. I've had to restart it a couple of times but I don't think any of those times were due to issues with the OpenWRT implementation.

I had issues with some of the Snapshot releases prior to the stable 25.12.x releases, but nothing stands out really since then.

This is a random question, and I can't check against stock as I went straight to OpenWRT, but does anyone have severe coil whine when serving traffic (from 100Mbps - ~ 1.5Gbps) over WiFi?

My BT8 AP is so... freaking loud, I can hear it when I download or upload things. I bought a different power supply, which seems to help a bit, but its ridiculous. Both units do this it sounds like.

It also creates so much noise on my microphone on my headset, the router is about 1m away from me. I can live with it.. but still, completely different to the TUF AX6000 it replaced.

I have no noise from mine at all, no coil whine regardless of load up to 1.2gbps.

No noise on two different BT8's here at 1+Gbps wireless. Is everything grounded correctly? Direct edit regdb to lower tx power and see if that helps. Enable WED?

Anecdotal evidence:
I had two TUF-AX6000 units' wireless die which caused a BoD (Bootloop of death). One of the very early telltale signs was increasing coil whine the instant wireless was brought up.

Note: Asus has great warranty support at 24-36 months. Pre-register now to save you time to in case. You may reach out and ask if coil whine is covered if it is crazy loud.

Sorry if this is a stupid question, but is the 6 GHz wifi working on latest firmware? I am unable to get it working.... Or is a snapshop release needed?

Options are to either patch and recompile or upload a modified regulatory DB. (not sure the legality of either, if you're in the U.S.)

I am in Sweden, does the same apply for me also?

6G = radio2. You shouldn't have any issue with latest stable after setting country code.

# SE: https://pts.se/globalassets/startpage/dokument/legala-dokument/foreskrifter/radio/beslutade_ptsfs-2018-3-undantagsforeskrifter.pdf
country SE: DFS-ETSI
	(2400 - 2483.5 @ 40), (100 mW)
	(5150 - 5250 @ 80), (200 mW), NO-OUTDOOR, AUTO-BW, wmmrule=ETSI
	(5250 - 5350 @ 80), (100 mW), NO-OUTDOOR, DFS, AUTO-BW, wmmrule=ETSI
	(5470 - 5725 @ 160), (500 mW), DFS, wmmrule=ETSI
	# short range devices (ETSI EN 300 440-1)
	(5725 - 5875 @ 80), (25 mW)
	# 6 GHz band
	(5945 - 6425 @ 320), (23), NO-OUTDOOR, wmmrule=ETSI
	# 60 GHz band channels 1-4 (ETSI EN 302 567)
	(57000 - 66000 @ 2160), (40)