ACS fails with 'Unable to collect survey data'

[Daniel Golle]

Hi!

I'm trying to use hostapd with automatic channel selection on a 5 GHz
mt76 radio. There are no other networks in my environment, so there are
also no scan results returned from the driver.
I'd be glad to know if this is actually supposed to work or known not
to work.

Calling hostapd looks like this:
Configuration file: /var/run/hostapd-phy0.conf
wlan0: interface state UNINITIALIZED->COUNTRY_UPDATE
ACS: Automatic channel selection started, this may take a bit
wlan0: interface state COUNTRY_UPDATE->ACS
wlan0: ACS-STARTED 
ACS: Unable to collect survey data
ACS: All study options have failed
Interface initialization failed
wlan0: interface state ACS->DISABLED
wlan0: AP-DISABLED 
ACS: Possibly channel configuration is invalid, please report this along with your config file.
ACS: Failed to start
wlan0: AP-DISABLED 
hostapd_free_hapd_data: Interface wlan0 wasn't started
nl80211: deinit ifname=wlan0 disabled_11b_rates=0
wlan0: interface state DISABLED->DISABLED
wlan0: interface state DISABLED->DISABLED
wlan0: AP-DISABLED 
hostapd_free_hapd_data: Interface wlan0 wasn't started

hostapd.conf looks like this:
driver=nl80211
logger_syslog=127
logger_syslog_level=2
logger_stdout=127
logger_stdout_level=2
country_code=DE
ieee80211d=1
ieee80211h=1
hw_mode=a
channel=acs_survey


ieee80211n=1
ht_coex=0
ht_capab=[HT40+][LDPC][SHORT-GI-20][SHORT-GI-40][TX-STBC][RX-STBC1]
vht_oper_chwidth=1
vht_oper_centr_freq_seg0_idx=-6
ieee80211ac=1
vht_capab=[RXLDPC][SHORT-GI-80][TX-STBC-2BY1][RX-STBC-1][MAX-A-MPDU-LEN-EXP0]

interface=wlan0
ctrl_interface=/var/run/hostapd
ap_isolate=1
disassoc_low_ack=1
preamble=1
wmm_enabled=1
ignore_broadcast_ssid=0
uapsd_advertisement_enabled=1
wpa_passphrase=topsecretpassword
auth_algs=1
wpa=2
wpa_pairwise=CCMP
ssid=OpenWrt
bridge=br-lan
wpa_key_mgmt=WPA-PSK
okc=0
disable_pmksa_caching=1
bssid=78:a3:51:0d:12:f5


Cheers


Daniel