Updated my WNDR4300v1 to 21.02.0.
After update 5GHz radio stopped working.
When connected serial cable and checked what is going on I got this:
[ 14.530922] ath9k 18100000.wmac: Direct firmware load for ath9k-eeprom-ahb-18100000.wmac.bin failed with error -2
[ 14.541374] ath9k 18100000.wmac: Falling back to sysfs fallback for: ath9k-eeprom-ahb-18100000.wmac.bin
What should I do to get my wifi working?