Dear list, I am currently trying to tune my R52n ath9k minipci card for maximum performance in a high interference city environment. Mode is 802.11n in the 5 GHz band. What I see is better download compared to an R52 ath5k in 802.11a mode, but worse upload. I suspect either that the 802.11n modulation is less robust to noise OR that AMSDU aggregation is in use and is worsening resiliency to interference. See this monitoring screenshot: https://pasteboard.co/o8ykSMG.png The first part is 802.11a, the second is 802.11n, and the third was obtained by limiting the uplink to legacy rates by: iw dev wlan0 set bitrates legacy-5 6 9 12 18 ht-mcs-5 The problem: Unfortunately, the result of that is that only the 6 Mb/s rate is used. When I allow any ht-mcs-5 rate, none of the legacy rates is ever selected and the throughput is worse. It seems that the wandering minstrel algorithm is failing. The other side is a Mikrotik router and it freely mixes legacy and mcs rates to get optimal throughput, the Linux driver does not. 1. How would I debug this? Last time I did it in Madwifi, minstrel had some debug stats in procfs. 2. How to find out if AMSDU aggregation is in use and to disable it to see if that is the thing hurting performance? The kernel version is 4.9.0 from Debian. Thanks for your insights, Tomas Vondra
