Hey there,
i am using a wrt1900acs (Linux openwrt 3.18.36 #8 SMP Thu Oct 13 11:43:34 CEST 2016 armv7l GNU/Linux) and have problems using some of the 5ghz channels:
my /etc/config/wireless looks like this:
config wifi-device 'radio0'
option type 'mac80211'
option channel '140'
option hwmode '11a'
...
root@openwrt:~# iwinfo wlan0 info
No such wireless device: wlan0
when i change the wireless config to channel 36:
config wifi-device 'radio0'
option type 'mac80211'
option channel '36'
reload with 'wifi' then the device apears:
iwinfo wlan0 freqlist
* 5.180 GHz (Channel 36)
5.200 GHz (Channel 40)
5.220 GHz (Channel 44)
5.240 GHz (Channel 48)
5.260 GHz (Channel 52)
5.280 GHz (Channel 56)
5.300 GHz (Channel 60)
5.320 GHz (Channel 64)
5.500 GHz (Channel 100)
5.520 GHz (Channel 104)
5.540 GHz (Channel 108)
5.560 GHz (Channel 112)
5.580 GHz (Channel 116)
5.600 GHz (Channel 120)
5.620 GHz (Channel 124)
5.640 GHz (Channel 128)
5.660 GHz (Channel 132)
5.680 GHz (Channel 136)
5.700 GHz (Channel 140)
Now, when i change it back and reload the conf it will work (listed correctly in iw freqlist) - until the next reboot.
Alternatively when i change it to channel 136, the frequency is set to channel 100 !?
Using the commandline i get:
root@openwrt:~# iw wlan0 set channel 136
command failed: Invalid argument (-22)
-- the listed frequencies from iw are not valid?
and
root@openwrt:~# iw wlan0 set channel 140
command failed: Invalid argument (-22)
which is really strange, because having this option in the conf and then reloading works