No 80211n possible with AR9220?
Dear ath9k-developers!
Dear hostapd-developers!
I cannot reach 802.11n-speeds using an Atheros-Chipset, that is said to be supported by ath9k:
http://wireless.kernel.org/en/users/Drivers/ath9k#supported_chipsets - see AR9220.
The long story:
I bought two brandnew Senao EMP-7605 Wireless Cards, which use the Atheros AR9220 chipset. The two cards are each plugged into a dedicated ALIX-Board from PCEngines and the system running is Debian Lenny with Kernel 2.6.32.10:
# uname -a Linux DebianLennyClient 2.6.32.10 #1 SMP Tue Mar 30 12:54:18 UTC 2010 i586 GNU/Linux
I compiled it on my own, it has the mac80211 compiled into the kernel (no module) and of course ath9k. hostapd comes with a git-snapshot from 2010-02-20, available here:
http://hostap.epitest.fi/gitweb/gitweb.cgi?p=hostap-06.git;a=summary
I kept my hostapd.conf as simple as I could just for checking, if I can reach functionality at all:
# cat hostapd.conf interface=wlan0 driver=nl80211 logger_syslog=-1 logger_syslog_level=2 logger_stdout=-1 logger_stdout_level=2 dump_file=/tmp/hostapd.dump ctrl_interface=/var/run/hostapd ctrl_interface_group=0 ssid=testsalat hw_mode=g channel=11 auth_algs=1
With this setup, I can do a
# iw wlan1 connect testsalat
and afterwards, a ping gets through:
# ping 192.168.55.1 PING 192.168.55.1 (192.168.55.1) 56(84) bytes of data. 64 bytes from 192.168.55.1: icmp_seq=1 ttl=64 time=258 ms 64 bytes from 192.168.55.1: icmp_seq=2 ttl=64 time=56.5 ms 64 bytes from 192.168.55.1: icmp_seq=3 ttl=64 time=54.9 ms
So I can reach main functionality. If now I go ahead an set up 802.11n, it stops working at all. My hostapd.conf is still the same as mentioned above with these additions:
wmm_enabled=1
wmm_ac_bk_cwmin=4
wmm_ac_bk_cwmax=10
wmm_ac_bk_aifs=7
wmm_ac_bk_txop_limit=0
wmm_ac_bk_acm=0
wmm_ac_be_aifs=3
wmm_ac_be_cwmin=4
wmm_ac_be_cwmax=10
wmm_ac_be_txop_limit=0
wmm_ac_be_acm=0
wmm_ac_vi_aifs=2
wmm_ac_vi_cwmin=3
wmm_ac_vi_cwmax=4
wmm_ac_vi_txop_limit=94
wmm_ac_vi_acm=0
wmm_ac_vo_aifs=2
wmm_ac_vo_cwmin=2
wmm_ac_vo_cwmax=3
wmm_ac_vo_txop_limit=47
wmm_ac_vo_acm=0
ieee80211n=1
ht_capab=[HT40-][SHORT-GI-40][DSSS_CCK-40]
The capabilities have been taken from this output:
# iw list
Wiphy phy0
Band 1:
Capabilities: 0x104e
HT20/HT40
SM Power Save disabled
RX HT40 SGI
No RX STBC
Max AMSDU length: 7935 bytes
DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: 8 usec (0x06)
HT TX/RX MCS rate indexes supported: 0-15
Frequencies:
* 2412 MHz [1] (20.0 dBm)
* 2417 MHz [2] (20.0 dBm)
* 2422 MHz [3] (20.0 dBm)
* 2427 MHz [4] (20.0 dBm)
* 2432 MHz [5] (20.0 dBm)
* 2437 MHz [6] (20.0 dBm)
* 2442 MHz [7] (20.0 dBm)
* 2447 MHz [8] (20.0 dBm)
* 2452 MHz [9] (20.0 dBm)
* 2457 MHz [10] (20.0 dBm)
* 2462 MHz [11] (20.0 dBm)
* 2467 MHz [12] (disabled)
* 2472 MHz [13] (disabled)
* 2484 MHz [14] (disabled)
Bitrates (non-HT):
* 1.0 Mbps
* 2.0 Mbps (short preamble supported)
* 5.5 Mbps (short preamble supported)
* 11.0 Mbps (short preamble supported)
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
Band 2:
Capabilities: 0x104e
HT20/HT40
SM Power Save disabled
RX HT40 SGI
No RX STBC
Max AMSDU length: 7935 bytes
DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: 8 usec (0x06)
HT TX/RX MCS rate indexes supported: 0-15
Frequencies:
* 5180 MHz [36] (20.0 dBm) (passive scanning, no IBSS)
* 5200 MHz [40] (20.0 dBm) (passive scanning, no IBSS)
* 5220 MHz [44] (20.0 dBm) (passive scanning, no IBSS)
* 5240 MHz [48] (20.0 dBm) (passive scanning, no IBSS)
* 5260 MHz [52] (disabled)
* 5280 MHz [56] (disabled)
* 5300 MHz [60] (disabled)
* 5320 MHz [64] (disabled)
* 5500 MHz [100] (disabled)
* 5520 MHz [104] (disabled)
* 5540 MHz [108] (disabled)
* 5560 MHz [112] (disabled)
* 5580 MHz [116] (disabled)
* 5600 MHz [120] (disabled)
* 5620 MHz [124] (disabled)
* 5640 MHz [128] (disabled)
* 5660 MHz [132] (disabled)
* 5680 MHz [136] (disabled)
* 5700 MHz [140] (disabled)
* 5745 MHz [149] (20.0 dBm) (passive scanning, no IBSS)
* 5765 MHz [153] (20.0 dBm) (passive scanning, no IBSS)
* 5785 MHz [157] (20.0 dBm) (passive scanning, no IBSS)
* 5805 MHz [161] (20.0 dBm) (passive scanning, no IBSS)
* 5825 MHz [165] (20.0 dBm) (passive scanning, no IBSS)
Bitrates (non-HT):
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
max # scan SSIDs: 4
Fragmentation threshold: 2346
RTS threshold: 2347
Supported interface modes:
* IBSS
* managed
* AP
* AP/VLAN
* monitor
* mesh point
Supported commands:
* new_interface
* set_interface
* new_key
* new_beacon
* new_station
* set_bss
* authenticate
* associate
* deauthenticate
* disassociate
* join_ibss
* set_wiphy_netns
* connect
* disconnectAccording to my understanding, this should do quite well, but as soon as I add "ieee80211n=1" to my hostapd.conf, I can't even get a ping through. The client associates, as told by the debug output of hostapd, but it's not able to ping. This is independant of using wpa_supplicant or iw to associate. So I am not able to test the performance of 802.11n on these cards at all. In addition, I am always connected with 1 Mbit/s, which shouldn't be correct either:
# iw dev wlan1 link
Connected to 00:0e:8e:24:52:2f (on wlan1)
SSID: testsalat
freq: 2462
RX: 40496 bytes (404 packets)
TX: 3046 bytes (38 packets)
signal: -48 dBm
tx bitrate: 1.0 MBit/sThis is my dmesg from boot-time:
# dmesg | grep ath [ 7.526966] ath: EEPROM regdomain: 0x37 [ 7.526981] ath: EEPROM indicates we should expect a direct regpair map [ 7.527000] ath: Country alpha2 being used: AT [ 7.527014] ath: Regpair used: 0x37 [ 8.321933] phy0: Selected rate control algorithm 'ath9k_rate_control' [ 8.335132] Registered led device: ath9k-phy0::radio [ 8.337203] Registered led device: ath9k-phy0::assoc [ 8.339262] Registered led device: ath9k-phy0::tx [ 8.341078] Registered led device: ath9k-phy0::rx
Are all of these observations due to bugs or am I misconfiguring my system somehow? If you need more debugging output, just tell me!
Kind regards,
Dennis
Quoted 8 lines · Dennis Borgmann
# iw dev wlan1 link
Connected to 00:0e:8e:24:52:2f (on wlan1)
SSID: testsalat
freq: 2462
RX: 40496 bytes (404 packets)
TX: 3046 bytes (38 packets)
signal: -48 dBm
tx bitrate: 1.0 MBit/sI tried AR9220 on the AP side and AR9280 on the station side. Everything worked fine with 802.11n. That's what I get on the client:
# iw dev wlan1 link
Connected to 00:26:5a:c2:4c:3d (on wlan1)
SSID: mike2
freq: 2462
RX: 111244 bytes (629 packets)
TX: 20186 bytes (176 packets)
signal: -23 dBm
tx bitrate: 117.0 MBit/s MCS 14I'm using the current linux-wireless on both sides, so that may be the reason. I tried channels 6 and 11. I tried no encryption and WPA2 with CCMP.
I saw the bitrate fall to 1 Mbps if there is no traffic, but it would immediately return to a high value once I start pinging the AP.
Signature · 2 lines
Regards, Pavel Roskin