arlit:

Model Buffalo WZR-HP-G300NH
Issue reproducible in commit r11486
Issue absent in Commit r11483

This device has one wifi device which is configured to provide at least two wifi-ifaces, each iface is disabled at startup; each iface got a different BSSID/maccaddr/ifname;

These wifi-interfaces are enabled/disabled manually by using a script: the script set one wifi-iface "disabled" param to either "0" or "1" (these changes are NOT saved using uci commit) and then runs the commands "wifi" and "ubus call network reload && /etc/init.d/dnsmasq reload"

• Steps to reproduce
  Enabling and then disabling both interfaces multiple times make wifi inoperable without a reboot.

SYSLOG detailing what happens when the issue manifests itself
{{{

Fri Jan 31 10:34:40 2020 user.notice root: user.notice "wps" (released: 2 sec.) HANDLER: (SCRIPT TO SET WIFI 2 ON)
Fri Jan 31 10:34:46 2020 daemon.notice hostapd: Configuration file: /var/run/hostapd-phy0.conf (phy wlan0-1) --> new PHY

Fri Jan 31 10:34:46 2020 daemon.err hostapd: Could not read interface wlan0-1 flags: No such device
Fri Jan 31 10:34:46 2020 daemon.notice hostapd: nl80211: Driver does not support authentication/association or connect commands
Fri Jan 31 10:34:46 2020 daemon.notice hostapd: nl80211: deinit ifname=wlan0-1 disabled_11b_rates=0
Fri Jan 31 10:34:46 2020 daemon.err hostapd: Could not read interface wlan0-1 flags: No such device
Fri Jan 31 10:34:46 2020 daemon.err hostapd: nl80211 driver initialization failed.
Fri Jan 31 10:34:46 2020 daemon.notice hostapd: wlan0-1: CTRL-EVENT-TERMINATING
Fri Jan 31 10:34:46 2020 daemon.err hostapd: hostapd_free_hapd_data: Interface wlan0-1 wasn't started
Fri Jan 31 10:34:46 2020 daemon.notice netifd: radio0 (9998): Command failed: Invalid argument
Fri Jan 31 10:34:48 2020 user.notice root: ip link set dev wlan0-1 up
Fri Jan 31 10:34:48 2020 daemon.notice netifd: radio0 (9998): ip: SIOCGIFFLAGS: No such device
Fri Jan 31 10:34:48 2020 daemon.notice netifd: radio0 (9998): Interface 0 setup failed: IFUP_ERROR
Fri Jan 31 10:35:29 2020 user.notice root: user.notice "wps" (released: 0 sec.) HANDLER: (SCRIPT TO SET WIFI 2 OFF)
Fri Jan 31 10:35:31 2020 daemon.notice netifd: radio0 (10236): WARNING: Variable 'data' does not exist or is not an array/object

Fri Jan 31 10:35:35 2020 daemon.notice hostapd: Configuration file: /var/run/hostapd-phy0.conf (phy wlan0-1) --> new PHY
Fri Jan 31 10:35:36 2020 daemon.err hostapd: Could not read interface wlan0-1 flags: No such device
Fri Jan 31 10:35:36 2020 daemon.notice hostapd: nl80211: Driver does not support authentication/association or connect commands
Fri Jan 31 10:35:36 2020 daemon.notice hostapd: nl80211: deinit ifname=wlan0-1 disabled_11b_rates=0
Fri Jan 31 10:35:36 2020 daemon.err hostapd: Could not read interface wlan0-1 flags: No such device
Fri Jan 31 10:35:36 2020 daemon.err hostapd: nl80211 driver initialization failed.
Fri Jan 31 10:35:36 2020 daemon.notice hostapd: wlan0-1: CTRL-EVENT-TERMINATING
Fri Jan 31 10:35:36 2020 daemon.err hostapd: hostapd_free_hapd_data: Interface wlan0-1 wasn't started
Fri Jan 31 10:35:36 2020 daemon.notice netifd: radio0 (10284): Command failed: Invalid argument
Fri Jan 31 10:35:37 2020 user.notice root: ip link set dev wlan0-1 up

Fri Jan 31 10:35:38 2020 daemon.notice netifd: radio0 (10284): ip: SIOCGIFFLAGS: No such device
Fri Jan 31 10:35:38 2020 daemon.notice netifd: radio0 (10284): Interface 0 setup failed: IFUP_ERROR
Fri Jan 31 10:35:48 2020 user.notice root: user.notice "wps" (released: 2 sec.) HANDLER: (SCRIPT TO SET WIFI 2 ON)
Fri Jan 31 10:35:49 2020 daemon.notice netifd: radio0 (10593): Command failed: Not found
Fri Jan 31 10:35:49 2020 daemon.notice netifd: radio0 (10593): command failed: No such device (-19)

Fri Jan 31 10:35:59 2020 daemon.notice hostapd: Configuration file: /var/run/hostapd-phy0.conf (phy wlan0-1) --> new PHY
Fri Jan 31 10:35:59 2020 daemon.err hostapd: Could not read interface wlan0-1 flags: No such device
Fri Jan 31 10:35:59 2020 daemon.notice hostapd: nl80211: Driver does not support authentication/association or connect commands
Fri Jan 31 10:35:59 2020 daemon.notice hostapd: nl80211: deinit ifname=wlan0-1 disabled_11b_rates=0
Fri Jan 31 10:35:59 2020 daemon.err hostapd: Could not read interface wlan0-1 flags: No such device
Fri Jan 31 10:35:59 2020 daemon.err hostapd: nl80211 driver initialization failed.
Fri Jan 31 10:35:59 2020 daemon.notice hostapd: wlan0-1: CTRL-EVENT-TERMINATING
Fri Jan 31 10:35:59 2020 daemon.err hostapd: hostapd_free_hapd_data: Interface wlan0-1 wasn't started
Fri Jan 31 10:35:59 2020 daemon.notice netifd: radio0 (10746): Command failed: Invalid argument
Fri Jan 31 10:36:01 2020 user.notice root: ip link set dev wlan0-1 up
Fri Jan 31 10:36:01 2020 daemon.notice netifd: radio0 (10746): ip: SIOCGIFFLAGS: No such device
Fri Jan 31 10:36:01 2020 daemon.notice netifd: radio0 (10746): Interface 0 setup failed: IFUP_ERROR
}}}

Sample wireless config
{{{

config wifi-device 'radio0'
option type 'mac80211'
option channel '1'
option hwmode '11g'
option path 'platform/ath9k'
option htmode 'HT40'

config wifi-iface 'wifinet0'
option device 'radio0'
option network 'wifi1'
option macaddr 'XX:XX:XX:XX:XX:AA'
option mode 'ap'
option ssid 'test1'
option encryption 'none'
option ifname 'wlan0-0'
option disabled '1'

config wifi-iface 'wifinet1'
option device 'radio0'
option network 'wifi2'
option macaddr 'XX:XX:XX:XX:XX:BB'
option mode 'ap'
option ssid 'test2'
option encryption 'none'
option ifname 'wlan0-1'
option disabled '1'

}}}