On Tue, Mar 29, 2011 at 9:36 AM, Felix Fietkau <[email protected]> wrote:
> On 2011-03-29 3:33 PM, Larry Vaden wrote:
>>
>> Good morning, ath9k devs and OpenWrt-users.
>>
>> Please excuse the cross post, not something we normally do.
>>
>> We have a particularly difficult situation in which we are trying to
>> achieve a stable link over 1.2 miles with the Ubiquiti M900 which uses
>> the AR9280 and thus 2X2 MIMO.
>>
>> We loaded OpenWrt trunk as a scientific control when we observed
>> spontaneous reboots on AirOS 5.2.1 and 5.3.
>>
>> There is only one tree in the Fresnel zone and it has few leaves this
>> time of year. An unlicensed SCADA operation is a few miles away,
>> using omnis at six water towers.
>>
>> To try to reduce the number of variables, we note with interest
>> MikroTik's statement below the sig and ask folks on ath9k-devel and
>> OpenWrt-users how to configure, e.g., OpenWrt to use only chain 0.
>>
>> Excerpts of dmesg for the AP are also below the sig. dmesg on the CPE is
>> quiet.
>>
>> If the objective of this email is unrelated, please offer any advice
>> to achieve desired operation.
>>
>> THANKS in advance for your help --- it is fully appreciated.
>
> To change the chainmask:
>
> wifi down
> echo 1 > /sys/kernel/debug/ieee80211/phy0/ath9k/rx_chainmask
> echo 1 > /sys/kernel/debug/ieee80211/phy0/ath9k/tx_chainmask
> wifi
>
> This might have some side effects as the HT capabilities are not
> recalculated (ath9k does not support the antenna control API yet), but it
> will configure the PHY to only use one chain, and the rate control is
> usually able to deal with that just fine.
>
> In order to debug this properly, please send a dump of the rate control
> stats of both sides:
> cat /sys/kernel/debug/ieee80211/phy0/netdev:wlan0/stations/*/rc_stats
>
> And also a dump of the channel busy time:
> iw wlan0 survey dump
>
> This might help narrow down the cause of this issue.
>
> - Felix
Felix,
Here's the requested information from the CPE end of the link, again
before any of the changes you suggest have been made:
wlan0: authenticate with 00:15:6d:4e:f1:46 (try 1)
wlan0: authenticated
wlan0: associate with 00:15:6d:4e:f1:46 (try 1)
wlan0: RX AssocResp from 00:15:6d:4e:f1:46 (capab=0x401 status=0 aid=1)
wlan0: associated
cfg80211: Calling CRDA to update world regulatory domain
cfg80211: World regulatory domain updated:
cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211: (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
wlan0: authenticate with 00:15:6d:4e:f1:46 (try 1)
wlan0: authenticated
wlan0: associate with 00:15:6d:4e:f1:46 (try 1)
wlan0: RX ReassocResp from 00:15:6d:4e:f1:46 (capab=0x401 status=0 aid=1)
wlan0: associated
root@OpenWrt:~# cat /etc/config/wireless
config wifi-device radio0
option type mac80211
option channel 5
option macaddr 00:15:6d:9c:16:df
option hwmode 11ng
option htmode HT20
list ht_capab SHORT-GI-40
list ht_capab TX-STBC
list ht_capab RX-STBC1
list ht_capab DSSS_CCK-40
option disabled 0
config wifi-iface
option device radio0
option network wan
option mode sta
option ssid OpenWrt
option encryption none
root@OpenWrt:~# cat /sys/kernel/debug/ieee80211/phy0/netdev:wlan0/stations/*/rc_
stats
type rate throughput ewma prob this prob this
succ/attempt success attempts
HT20/LGI TtPMCS0 3.2 51.6 100.0 1( 1)
380 4440
HT20/LGI MCS1 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS2 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS3 0.0 0.0 0.0 0( 0)
0 4
HT20/LGI MCS4 0.0 0.0 0.0 0( 0)
0 4
HT20/LGI MCS5 0.0 0.0 0.0 0( 0)
0 4
HT20/LGI MCS6 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS7 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS8 0.0 3.9 0.0 0( 0)
3 56
HT20/LGI MCS9 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS10 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS11 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS12 0.0 0.0 0.0 0( 0)
0 4
HT20/LGI MCS13 0.0 0.0 0.0 0( 0)
0 4
HT20/LGI MCS14 0.0 0.0 0.0 0( 0)
0 5
HT20/LGI MCS15 0.0 0.0 0.0 0( 0)
0 4
Total packet count:: ideal 657 lookaround 74
Average A-MPDU length: 1.0
root@OpenWrt:~# iw wlan0 survey dump
Survey data from wlan0
frequency: 2412 MHz
noise: -111 dBm
channel active time: 59 ms
channel busy time: 14 ms
channel receive time: 2 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2417 MHz
noise: -108 dBm
channel active time: 59 ms
channel busy time: 14 ms
channel receive time: 2 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2422 MHz
noise: -113 dBm
channel active time: 59 ms
channel busy time: 14 ms
channel receive time: 0 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2427 MHz
noise: -122 dBm
channel active time: 59 ms
channel busy time: 12 ms
channel receive time: 2 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2432 MHz [in use]
noise: -121 dBm
channel active time: 107955637 ms
channel busy time: 23134560 ms
channel receive time: 7555724 ms
channel transmit time: 5890963 ms
Survey data from wlan0
frequency: 2437 MHz
noise: -116 dBm
channel active time: 59 ms
channel busy time: 9 ms
channel receive time: 1 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2442 MHz
noise: -97 dBm
channel active time: 59 ms
channel busy time: 8 ms
channel receive time: 0 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2447 MHz
noise: -95 dBm
channel active time: 59 ms
channel busy time: 8 ms
channel receive time: 0 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2452 MHz
noise: -98 dBm
channel active time: 59 ms
channel busy time: 8 ms
channel receive time: 0 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2457 MHz
noise: -95 dBm
channel active time: 59 ms
channel busy time: 8 ms
channel receive time: 0 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2462 MHz
noise: -115 dBm
channel active time: 59 ms
channel busy time: 8 ms
channel receive time: 0 ms
channel transmit time: 1 ms
Survey data from wlan0
frequency: 2467 MHz
Survey data from wlan0
frequency: 2472 MHz
Survey data from wlan0
frequency: 2484 MHz
root@OpenWrt:~#
_______________________________________________
openwrt-users mailing list
[email protected]
https://lists.openwrt.org/mailman/listinfo/openwrt-users
