ACS survey errors - "missing noise floor", "insufficient data"; no 40HZ usage?

PGNet Dev pgnet.dev at gmail.com
Wed Mar 29 12:10:27 PDT 2017 

With

	hostapd -v
		hostapd v2.7-devel-hostap_2_6-871-g0b287a2+
		User space daemon for IEEE 802.11 AP management,
		IEEE 802.1X/WPA/WPA2/EAP/RADIUS Authenticator
		Copyright (c) 2002-2017, Jouni Malinen <j at w1.fi> and contributors


For my wifi device,

	ALFA AWUS052NH

frequencies include

	iw list
		...
		Frequencies:
			...
			* 5745 MHz [149] (30.0 dBm)
			* 5755 MHz [151] (30.0 dBm)
			* 5765 MHz [153] (30.0 dBm)
			* 5785 MHz [157] (30.0 dBm)
			* 5795 MHz [159] (30.0 dBm)
			* 5805 MHz [161] (30.0 dBm)
			* 5825 MHz [165] (30.0 dBm)
			...
			Supported commands:


I've done a WiFi scan, using a phone, of those channels.

Atm,  0 usage of any of them where I'm located.  I.e., no congestion which might prevent 40MHz ops.

I've added those to the allowed channel selection set,

	chanlist=149 151 153 157 159 161 165

My ht capabilities are set as

	ht_capab=[HT40+][GF][SHORT-GI-40][TX-STBC][RX-STBC2][MAX-AMSDU-3839]

I enable ACS

	channel=acs_survey

and restart.

I end up connected to Channel=149, and functional, but logs show a bunch of ACS-related errors

	Mar 29 11:55:25 test hostapd[5894]: wlp0s31d1u3: interface state ENABLED->DISABLED
	Mar 29 11:55:25 test hostapd: wlp0s31d1u3: STA 10:31:d4:c3:22:a4 MLME: MLME-DEAUTHENTICATE.indication(10:31:d4:c3:22:a4, 1)
	Mar 29 11:55:25 test hostapd[5894]: wlp0s31d1u3: AP-STA-DISCONNECTED 10:31:d4:c3:22:a4
	Mar 29 11:55:25 test hostapd[5894]: nl80211: disabling multicast to unicast failed with -16 (Device or resource busy) on interface wlp0s31d1u3
	Mar 29 11:55:25 test hostapd[5894]: wlp0s31d1u3: AP-DISABLED
	Mar 29 11:55:25 test hostapd[5894]: wlp0s31d1u3: CTRL-EVENT-TERMINATING
	Mar 29 11:55:25 test hostapd[5894]: nl80211: deinit ifname=wlp0s31d1u3 disabled_11b_rates=0
	Mar 29 11:55:26 test hostapd[13759]: Configuration file: /etc/hostapd/hostapd.conf
	Mar 29 11:55:26 test hostapd[13759]: wlp0s31d1u3: interface state UNINITIALIZED->COUNTRY_UPDATE
	Mar 29 11:55:26 test hostapd[13759]: ACS: Automatic channel selection started, this may take a bit
	Mar 29 11:55:26 test hostapd[13759]: wlp0s31d1u3: interface state COUNTRY_UPDATE->ACS
	Mar 29 11:55:26 test hostapd[13759]: wlp0s31d1u3: ACS-STARTED
	Mar 29 11:55:32 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:32 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:32 test hostapd[13759]: handle_probe_req: send failed
	Mar 29 11:55:32 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:32 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:32 test hostapd[13759]: handle_probe_req: send failed
	Mar 29 11:55:45 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:45 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:45 test hostapd[13759]: handle_probe_req: send failed
	Mar 29 11:55:45 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:45 test hostapd[13759]: Failed to check if DFS is required; ret=-1
	Mar 29 11:55:45 test hostapd[13759]: handle_probe_req: send failed
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Channel 149 has insufficient survey data
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Channel 149 has insufficient survey data
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Channel 149 has insufficient survey data
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Survey is missing noise floor
	Mar 29 11:55:51 test hostapd[13759]: ACS: Channel 149 has insufficient survey data
	Mar 29 11:55:51 test hostapd[13759]: wlp0s31d1u3: ACS-COMPLETED freq=5745 channel=149
	Mar 29 11:55:51 test hostapd[13759]: wlp0s31d1u3: interface state ACS->HT_SCAN
	Mar 29 11:55:52 test hostapd[13759]: Using interface wlp0s31d1u3 with hwaddr 02:d1:ff:34:15:10 and ssid "testMyWifi"
	Mar 29 11:55:52 test hostapd[13759]: nl80211: disabling multicast to unicast failed with -16 (Device or resource busy) on interface wlp0s31d1u3
	Mar 29 11:55:52 test hostapd[13759]: wlp0s31d1u3: interface state HT_SCAN->ENABLED
	Mar 29 11:55:52 test hostapd[13759]: wlp0s31d1u3: AP-ENABLED

and, afaict, there's no indication of 40MHz channel-pairing

	iwconfig wlp0s31d1u3
		wlp0s31d1u3  IEEE 802.11  Mode:Master  Tx-Power=30 dBm
		          Retry short limit:7   RTS thr:off   Fragment thr:off
		          Power Management:off


my config supposedly supports AP scanning,

	iw list | egrep -i "scan|acs"
		max # scan SSIDs: 4
		max scan IEs length: 2257 bytes
		max # sched scan SSIDs: 0
		max # scan plans: 1
		max scan plan interval: -1
		max scan plan iterations: 0
		Device supports low priority scan.
		Device supports scan flush.
		Device supports AP scan.

What's missing re: my ACS scan, and 40MHz usage?

More information about the Hostap mailing list