Nice, but would it not be less CPU (given this is running every 30 to 60 seconds) to pre-compute the command once and just use the values that work for your deployment?
So like this:
# 5Ghz – ch 161
iw dev wlan1 scan trigger freq 5805 flush
# 2.4GHz - ch 8
iw dev wlan0 scan trigger freq 2447 flush
BTW- this works fine on MT7621 / 7603 as well as the C7 (I have both). So this workaround seems to point the finger at something common to several (all?) platforms.
Here is a NetSpot signal scan for the past 30 minutes showing how even in a crowded WiFi environment that causes the OpenWRT APs to lower their 2.4 radio signals, is maintained at a high level with a scan every 60 seconds. Top trace (Brown is the 2.4 radio, next one down (blue) is the 5Ghz radio. AP is 3' from my MacBook Pro running NetSpot.
