5Ghz Wi-Fi doesn't work if DFS channel used on TP-Link Archer C6(EU) Ver3.20

[kt315ua]

Basic working configuration: dmesg.txt wireless.txt

Known non-DFS channels: 36, 40, 44, 48, 149, 153, 157, and 161

Steps to reproduce:

• Set Wi-Fi 5GHz channel to 52 (dfs channel)

Result:

• 5GHz Wi-Fi stops working:

  Mon Sep 12 07:54:17 2022 daemon.notice hostapd: wlan1: interface state HT_SCAN->DFS
  Mon Sep 12 07:54:17 2022 daemon.notice hostapd: wlan1: DFS-CAC-START freq=5260 chan=52 sec_chan=1, width=1, seg0=58, seg1=0, cac_time=60s
  Mon Sep 12 07:54:17 2022 daemon.err hostapd: DFS start_dfs_cac() failed, -1
  Mon Sep 12 07:54:17 2022 daemon.err hostapd: Interface initialization failed
  

• Can't use 160Mhz bandwidth, seems because it overlaps with DFS-channels

logread.txt

System

Hostname	OpenWrt
Model	TP-Link Archer C6 v3
Architecture	MediaTek MT7621 ver:1 eco:3
Target Platform	ramips/mt7621
Firmware Version	OpenWrt 22.03.0 r19685-512e76967f / LuCI openwrt-22.03 branch git-22.245.77528-487e58a
Kernel Version	5.10.138

Hardware: TP-Link Archer C6(EU) Ver3.20

[Borromini]

The MT7613BE radio does not support DFS by design.

[sad-goldfish]

Not exactly a solution but setting list hostapd_options 'ieee80211h=0' in /etc/config/wireless should disable DFS and seems to avoid channels where it is necessary.

[kt315ua]

The MT7613BE radio does not support DFS by design.

Ok, maybe it's a fact, but it's not solution for a system bug. If this chipset/platform doesn't support DFS, why it trying to be used? Where i can look for that?