RT73 and rate control

Live forum: http://rt2x00.serialmonkey.com/viewtopic.php?t=6205


14-02-2012 00:01:14


I've just had a need to get out one of my RT73 adapters and discovered that I'm getting very poor throughput. I tried upgrading to Ubuntu's compat-wireless 3.1 drivers which should be close to current but that hasn't helped (as far as I can tell driver version has been at 2.3.0 for ages so is no help diagnosing how old a version I'm running).

I'm suspicious of the rate control algorithm as /sys/kernel/debug/ieee80211/phy0/netdev\wlan0/stations/<ap_mac_address>/rc_stats indicates it is running at 54 Mbps all the time except when doing lookaround and almost every packet at every rate is succeeding, yet actual measured throughput is only around 2-3 Mbps. I remember that there are issues with all of the RT2x00 USB devices getting the tx status information and am wondering if the rate control algorithm (minstrel_ht) is believing for some reason that packets for which no tx status is available have succeeded.

Based on comments elsewhere I've tried disabling power management and that makes no difference and I've tried setting nohwcrypt=1 and that just results in authentication failing so I guess the software crypto interface is currently broken.

Any helpful hints before I go poking around further?