Trying to enable 5 Ghz 160Mhz on a Mediatek MT7915 to no avail

Hardware Questions and Recommendations
1

I got one mini PCIe module from Aliexpress and it works fine except for 5Ghz 160Mhz mode. I have the country settings on GB and from what I see on Wikipedia, 160Hz is allowed. I even tried selecting the channel manually to pick one that is for sure allowed in the UK.But It always disables itself. Here is the log I get:

Tue Mar 14 15:28:20 2023 daemon.notice hostapd: Remove interface 'wlan1'
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: interface state ENABLED->DISABLED
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: AP-DISABLED
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: CTRL-EVENT-TERMINATING
Tue Mar 14 15:28:20 2023 daemon.err hostapd: rmdir[ctrl_interface=/var/run/hostapd]: Permission denied
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: nl80211: deinit ifname=wlan1 disabled_11b_rates=0
Tue Mar 14 15:28:20 2023 daemon.notice netifd: Network device 'wlan1' link is down
Tue Mar 14 15:28:20 2023 kern.info kernel: [ 3713.004607] device wlan1 left promiscuous mode
Tue Mar 14 15:28:20 2023 kern.info kernel: [ 3713.005305] br-lan: port 2(wlan1) entered disabled state
Tue Mar 14 15:28:20 2023 daemon.notice netifd: Wireless device 'radio1' is now down
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: Configuration file: /var/run/hostapd-phy1.conf (phy wlan1) --> new PHY
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: interface state UNINITIALIZED->COUNTRY_UPDATE
Tue Mar 14 15:28:20 2023 kern.info kernel: [ 3713.233203] br-lan: port 2(wlan1) entered blocking state
Tue Mar 14 15:28:20 2023 kern.info kernel: [ 3713.233829] br-lan: port 2(wlan1) entered disabled state
Tue Mar 14 15:28:20 2023 kern.info kernel: [ 3713.234586] device wlan1 entered promiscuous mode
Tue Mar 14 15:28:20 2023 kern.info kernel: [ 3713.235312] br-lan: port 2(wlan1) entered blocking state
Tue Mar 14 15:28:20 2023 kern.info kernel: [ 3713.235802] br-lan: port 2(wlan1) entered forwarding state
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: interface state COUNTRY_UPDATE->HT_SCAN
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: interface state HT_SCAN->DFS
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: DFS-CAC-START freq=5260 chan=52 sec_chan=1, width=2, seg0=50, seg1=0, cac_time=60s
Tue Mar 14 15:28:20 2023 daemon.err hostapd: nl80211: kernel reports: (extension) channel is disabled
Tue Mar 14 15:28:20 2023 daemon.err hostapd: DFS start_dfs_cac() failed, -1
Tue Mar 14 15:28:20 2023 daemon.err hostapd: Interface initialization failed
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: interface state DFS->DISABLED
Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: AP-DISABLED
Tue Mar 14 15:28:21 2023 kern.info kernel: [ 3714.043503] br-lan: port 2(wlan1) entered disabled state
Tue Mar 14 15:28:21 2023 daemon.notice netifd: Wireless device 'radio1' is now up

And the output if iw reg get

root@OpenWrt:/etc/modules.d# iw reg get
global
country GB: DFS-ETSI
	(2400 - 2483 @ 40), (N/A, 20), (N/A)
	(5150 - 5250 @ 80), (N/A, 23), (N/A), NO-OUTDOOR, AUTO-BW
	(5250 - 5350 @ 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS, AUTO-BW
	(5470 - 5730 @ 160), (N/A, 26), (0 ms), DFS
	(5725 - 5850 @ 80), (N/A, 23), (N/A), NO-OUTDOOR
	(5925 - 6425 @ 160), (N/A, 23), (N/A), NO-OUTDOOR
	(57000 - 71000 @ 2160), (N/A, 40), (N/A)

Can anyone help explain what is going on?
Using OpenWrt 22.03.2 r19803-9a599fee93 / LuCI openwrt-22.03 branch git-22.288.45147-96ec0cd

as a virtual machine on Proxmox, with the PCIe wifi card passed through.

2

I would try again with latest master snapshots...

3

Just upgraded to latest 22.03.3. Same problem unfortunately

4

In the UK a 160Mhz channel width will guarantee you're on a DFS channel.

daemon.notice hostapd: wlan1: interface state DFS->DISABLED

The maximum width you can use without running afoul of DFS is 80MHz (channels 36 - 48)

5

Yeah but that is not really a problem right? It will just scan to check whether the channel is used by some radars, and if not activate after a few minutes. But it doesn't seem to me that it is doing that.

6

I edited my question, was running iw reg get on the host machine :man_facepalming:
It seems to me that wlan1 is trying to start a 160Mhz mode on a channel range that does not support it ?

Tue Mar 14 15:28:20 2023 daemon.notice hostapd: wlan1: DFS-CAC-START freq=5260 chan=52 sec_chan=1, width=2, seg0=50, seg1=0, cac_time=60s

while 160 is only available for 5470 - 5720, 5925-6425 ? Could that be it? And if so why is it picking an impossible frequency?

EDIT: I tried setting the frequency manually to channel 100 , 5500Mhz but it doesn't make any difference

7

On this page some AX routers are described as not supporting 160Mhz at 5Ghz. However, others that use a similar Wi-Fi chip to mine (MT7915) seem to be fine. Mystery

8

Interestingly enough, the DFS scanning works just fine on 80 Mhz, here is the log

Wed Mar 15 01:18:05 2023 daemon.notice hostapd: ACS: Automatic channel selection started, this may take a bit
Wed Mar 15 01:18:05 2023 daemon.notice hostapd: wlan1: interface state COUNTRY_UPDATE->ACS
Wed Mar 15 01:18:05 2023 daemon.notice hostapd: wlan1: ACS-STARTED
Wed Mar 15 01:18:06 2023 daemon.notice netifd: Wireless device 'radio1' is now up
Wed Mar 15 01:18:07 2023 daemon.info dnsmasq[1]: read /etc/hosts - 4 addresses
Wed Mar 15 01:18:07 2023 daemon.info dnsmasq[1]: read /tmp/hosts/dhcp.cfg01411c - 0 addresses
Wed Mar 15 01:18:21 2023 daemon.notice hostapd: wlan1: ACS-COMPLETED freq=5260 channel=52
Wed Mar 15 01:18:21 2023 daemon.notice hostapd: wlan1: interface state ACS->HT_SCAN
Wed Mar 15 01:18:21 2023 daemon.notice hostapd: Switch own primary and secondary channel to get secondary channel with no Beacons from other BSSes
Wed Mar 15 01:18:21 2023 daemon.notice hostapd: wlan1: interface state HT_SCAN->DFS
Wed Mar 15 01:18:21 2023 daemon.notice hostapd: wlan1: DFS-CAC-START freq=5280 chan=56 sec_chan=-1, width=1, seg0=58, seg1=0, cac_time=60s
Wed Mar 15 01:19:24 2023 daemon.notice hostapd: wlan1: DFS-CAC-COMPLETED success=1 freq=5280 ht_enabled=0 chan_offset=0 chan_width=3 cf1=5290 cf2=0
Wed Mar 15 01:19:24 2023 daemon.notice netifd: Network device 'wlan1' link is up
Wed Mar 15 01:19:24 2023 kern.info kernel: [21339.038566] IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
Wed Mar 15 01:19:24 2023 kern.info kernel: [21339.039188] br-lan: port 3(wlan1) entered blocking state
Wed Mar 15 01:19:24 2023 kern.info kernel: [21339.039742] br-lan: port 3(wlan1) entered forwarding state
Wed Mar 15 01:19:24 2023 daemon.notice hostapd: wlan1: interface state DFS->ENABLED
Wed Mar 15 01:19:24 2023 daemon.notice hostapd: wlan1: AP-ENABLED

Hopefully someone can shed some light on why it fails on 160Mhz

9

This module operates the MT7915 in DBDC mode. Since part of the chip's DSP capability is diverted to support the simultaneous 2 GHz operation of DBDC, 160 MHz on 5 GHz is not possible.

1 Like
10

you need a 4x4 mt7915 card for 2x2 160 Mhz

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11

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