[FS#44] Ath9k - TX performance regression on greater coverage settings

[LEDE Bugs]

The following task has a new comment added:

FS#44 - Ath9k - TX performance regression on greater coverage settings
User who did this - Koen Vandeputte (xback)

----------
Hi Bluse,

//2,4 GHz HT20//
I'm testing on 5GHz IBSS mode


//on Laptop A: iperf -s -u
on Laptop B: iperf -c IP(Laptop_A) -u -l 1400 -b 100M -t 30//

Could you try:
Laptop A: iperf -s
Laptop B: iperf -c IP -i 1 -t 30



//scenario 1: distance set to 14000
udp throughput is ~20MBit/s
aggregates ~ 2000 (from xmit)
max frames per aggregate: 31 (from /sys/kernel/debug/ieee80211/phy0/netdev\:wlan0/stations/MAC_Adress/rc_stats) //

Did you restart the iperf client on B after increasing the Cov Class?

In my case:
- When I start on 50m i get ~55Mbit/s
- When changing to 14000m on Device B while iperf is running, it drops to ~35Mbit/s (normal)
- When i stop iperf client on B, and restart it again, **I'm stuck at 6Mbit/s**


When checking this part:

//aggregates ~ 2000 (from xmit)
max frames per aggregate: 31 (from /sys/kernel/debug/ieee80211/phy0/netdev\:wlan0/stations/MAC_Adress/rc_stats) //

In step1: Avg Aggregated frames: ~6.5
In step2: Avg Aggregated frames: ~2.5
In step3: Avg Aggregated frames: 1.0


**step1 bw:**
[  4]  17.00-18.01  sec  8.57 MBytes  71.4 Mbits/sec    0    400 KBytes       
[  4]  18.01-19.01  sec  8.39 MBytes  70.5 Mbits/sec    0    400 KBytes       
[  4]  19.01-20.00  sec  7.93 MBytes  66.8 Mbits/sec    0    400 KBytes       
[  4]  20.00-21.00  sec  8.50 MBytes  71.1 Mbits/sec    0    400 KBytes


**step2 bw:**
[  4]  13.00-14.00  sec  8.49 MBytes  71.3 Mbits/sec    0    387 KBytes       
[  4]  14.00-15.00  sec  8.59 MBytes  71.9 Mbits/sec    0    387 KBytes       
[  4]  15.00-16.00  sec  8.42 MBytes  70.7 Mbits/sec    0    387 KBytes       
[  4]  16.00-17.00  sec  3.47 MBytes  29.2 Mbits/sec    0    387 KBytes     (iw phy0 set distance 14000)  
[  4]  17.00-18.00  sec  3.31 MBytes  27.7 Mbits/sec    0    387 KBytes       
[  4]  18.00-19.00  sec  3.05 MBytes  25.6 Mbits/sec    0    387 KBytes 

**Step3 bw:**
[  4] 215.00-216.00 sec   905 KBytes  7.41 Mbits/sec    0   31.1 KBytes       
[  4] 216.00-217.00 sec   970 KBytes  7.95 Mbits/sec    0   31.1 KBytes       
[  4] 217.00-218.00 sec   781 KBytes  6.39 Mbits/sec    0   31.1 KBytes       
[  4] 218.00-219.00 sec   823 KBytes  6.74 Mbits/sec    0   31.1 KBytes



IBSS wpa_supplicant config settings for both ends:

ctrl_interface=DIR=/tmp/run/wpa_supplicant GROUP=root
update_config=1
ap_scan=2
country=BE
beacon_int=100
network={
	ssid="TESTCHAN136"
	frequency=5680
	bssid=F8:79:77:57:AA:7D
	mode=1
	disable_ht=0
	disable_ht40=0
	disable_sgi=1
	proto=WPA2
	key_mgmt=WPA-PSK
	pairwise=CCMP
	group=CCMP
	psk="debugsessionpass"
}


Please let me know if you need more info,
Thanks again,

Koen
----------

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=44#comment185