Hi!
What does a driver (rtl8xxxu) need to do to make the rate control work?
I thought it's like this:
1) don't set HAS_RATE_CONTROL
2) tell the chip to use the rate from tx_info->control.rates[0]
3) report if the frame was acked or not
But it's not that easy. I'm always getting MCS0. Currently rtl8xxxu
doesn't ask the chip for TX reports and always sets IEEE80211_TX_STAT_ACK.
I thought this would get me MCS7 for all data frames, but it doesn't.
The rc_stats file from debugfs looks like this after using the connection for a while:
best ____________rate__________ ____statistics___ _____last____ ______sum-of________
mode guard # rate [name idx airtime max_tp] [avg(tp) avg(prob)] [retry|suc|att] [#success | #attempts]
HT20 LGI 1 ABCDPS MCS0 0 1477 5.6 0.0 0.0 1 0 0 0 0
HT20 LGI 1 S MCS1 1 738 10.6 0.0 0.0 0 0 0 0 0
HT20 LGI 1 MCS2 2 492 14.9 0.0 0.0 0 0 0 0 0
HT20 LGI 1 MCS3 3 369 18.8 0.0 0.0 0 0 0 0 0
HT20 LGI 1 S MCS4 4 246 25.4 0.0 0.0 0 0 0 0 0
HT20 LGI 1 MCS5 5 185 30.7 0.0 0.0 0 0 0 0 0
HT20 LGI 1 MCS6 6 164 33.0 0.0 0.0 0 0 0 0 0
HT20 LGI 1 MCS7 7 148 35.1 0.0 0.0 0 0 0 0 0
HT20 SGI 1 S MCS0 64 1329 6.2 0.0 0.0 0 0 0 0 0
HT20 SGI 1 MCS1 65 665 11.6 0.0 0.0 0 0 0 0 0
HT20 SGI 1 MCS2 66 443 16.3 0.0 0.0 0 0 0 0 0
HT20 SGI 1 MCS3 67 332 20.4 0.0 0.0 0 0 0 0 0
HT20 SGI 1 S MCS4 68 222 27.2 0.0 0.0 0 0 0 0 0
HT20 SGI 1 MCS5 69 166 32.8 0.0 0.0 0 0 0 0 0
HT20 SGI 1 MCS6 70 148 35.1 0.0 0.0 0 0 0 0 0
HT20 SGI 1 MCS7 71 133 37.3 0.0 0.0 0 0 0 0 0
HT40 LGI 1 S MCS0 128 711 10.9 0.0 0.0 0 0 0 0 0
HT40 LGI 1 MCS1 129 356 19.4 0.0 0.0 0 0 0 0 0
HT40 LGI 1 MCS2 130 237 26.0 0.0 0.0 0 0 0 0 0
HT40 LGI 1 MCS3 131 178 31.4 0.0 0.0 0 0 0 0 0
HT40 LGI 1 S MCS4 132 119 39.6 0.0 0.0 0 0 0 0 0
HT40 LGI 1 MCS5 133 89 45.6 0.0 0.0 0 0 0 0 0
HT40 LGI 1 MCS6 134 79 48.0 0.0 0.0 0 0 0 0 0
HT40 LGI 1 MCS7 135 71 50.2 0.0 0.0 0 0 0 0 0
HT40 SGI 1 S MCS0 192 640 12.0 0.0 0.0 0 0 0 0 0
HT40 SGI 1 MCS1 193 320 21.0 0.0 0.0 0 0 0 0 0
HT40 SGI 1 MCS2 194 214 27.9 0.0 0.0 0 0 0 0 0
HT40 SGI 1 MCS3 195 160 33.5 0.0 0.0 0 0 0 0 0
HT40 SGI 1 MCS4 196 107 41.8 0.0 0.0 0 0 0 0 0
HT40 SGI 1 MCS5 197 80 47.8 0.0 0.0 0 0 0 0 0
HT40 SGI 1 MCS6 198 71 50.1 0.0 0.0 0 0 0 0 0
HT40 SGI 1 MCS7 199 64 52.2 0.0 0.0 0 0 0 0 0
Total packet count:: ideal 4 lookaround 1
Average # of aggregated frames per A-MPDU: 1.0
It looks like the rate control algorithm is not getting any information. (Also, why are no CCK rates listed? With mt7601u there are CCK rates too.)
What to do?
