No 40MHz support on MT7620A based routers, support only when Wifi client are defined

Installing and Using OpenWrt Network and Wireless Configuration
1

Hello and I hope you can help me. The problem with my router (YOUKU YK-L1, Opw 21.01) is that the 40mhz mode under Wifi N does not only work if an access point is defined. However, if I log a wifi client into a different network, both of them transmit at 40mhz. I suspect it's a bug. Thanks for your help in advance.

My Config ...

config wifi-device 'radio0'
        option type 'mac80211'
        option hwmode '11g'
        option path 'platform/10180000.wmac'
        option cell_density '0'
        option country 'DE'
        option htmode 'HT40'
        option channel 'auto'

config wifi-iface 'wifinet0'
        option device 'radio0'
        option mode 'sta'
        option network 'wwan'
        option ssid 'W7020_OWT'
        option encryption 'psk2'
        option key 'secret'

config wifi-iface 'wifinet1'
        option device 'radio0'

when it"s not work in 40mhz mode

config wifi-device 'radio0'
        option type 'mac80211'
        option hwmode '11g'
        option path 'platform/10180000.wmac'
        option cell_density '0'
        option country 'DE'
        option htmode 'HT40'
        option channel 'auto'

config wifi-iface 'wifinet1'
        option device 'radio0'
        option mode 'ap'
        option ssid 'OpenWrt'
        option encryption 'none'
        option network 'lan'
2

Try taking channel off of 'auto' and manually select one.

3

If you are in environments where you won't find a completely silent 40MHz slice of 2.4GHz spectrum, the IEEE 802.11 standard commands you to use only 20MHz channels at max.
You can violate the standard by setting a channel manually as well as adding option noscan '1' to the wifi-device section.

2 Likes