Jérôme Pouiller <jerome.pouiller@xxxxxxxxxx> writes: > From: Felipe Negrelli Wolter <felipe.negrelliwolter@xxxxxxxxxx> > > When frames are sent over the air, the device always applies the data > rates in descending order. The driver assumed Minstrel also provided > rate in descending order. > > However, in some cases, Minstrel can a choose a fallback rate greater > than the primary rate. In this case, the two rates was inverted, the > device try highest rate first and we get many retries. > > Since the device always apply rates in descending order. The workaround > is to drop rate when it higher than its predecessor in the rate list. > Thus [ 4, 5, 3 ] become [ 4, 3 ]. > > This patch has been tested in isolated room with a series of > attenuators. Here are the Minstrel statistics with 80dBm of attenuation: > > Without the fix: > > 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 S MCS0 0 1477 5.6 5.2 82.7 3 0 0 3 4 > HT20 LGI 1 MCS1 1 738 10.6 0.0 0.0 0 0 0 0 1 > HT20 LGI 1 D MCS2 2 492 14.9 13.5 81.5 5 0 0 5 9 > HT20 LGI 1 C MCS3 3 369 18.8 17.6 84.3 5 0 0 76 96 > HT20 LGI 1 A P MCS4 4 246 25.4 22.4 79.5 5 0 0 11268 14026 > HT20 LGI 1 B S MCS5 5 185 30.7 19.7 57.7 5 8 9 3918 9793 > HT20 LGI 1 MCS6 6 164 33.0 0.0 0.0 5 0 0 6 102 > HT20 LGI 1 MCS7 7 148 35.1 0.0 0.0 0 0 0 0 44 > > With the fix: > > 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 S MCS0 0 1477 5.6 1.8 28.6 1 0 0 1 5 > HT20 LGI 1 DP MCS1 1 738 10.6 9.7 82.6 4 0 0 14 34 > HT20 LGI 1 MCS2 2 492 14.9 9.2 55.4 5 0 0 52 77 > HT20 LGI 1 B S MCS3 3 369 18.8 15.6 74.9 5 1 1 417 554 > HT20 LGI 1 A MCS4 4 246 25.4 16.7 59.2 5 1 1 13812 17951 > HT20 LGI 1 C S MCS5 5 185 30.7 14.0 41.0 5 1 5 57 640 > HT20 LGI 1 MCS6 6 164 33.0 0.0 0.0 0 0 1 0 48 > HT20 LGI 1 S MCS7 7 148 35.1 0.0 0.0 0 0 0 0 36 > > We can notice the device try now to send with lower rates (and high > success rates). At the end, we measured 20-25% better throughput with > this patch. > > Fixes: 9bca45f3d6924 "staging: wfx: allow to send 802.11 frames" > Tested-by: Olivier Souloumiac <olivier.souloumiac@xxxxxxxxxx> > Tested-by: Alexandr Suslenko <suslenko.o@ajax.systems> > Reported-by: Alexandr Suslenko <suslenko.o@ajax.systems> > Co-developed-by: Jérôme Pouiller <jerome.pouiller@xxxxxxxxxx> > Signed-off-by: Jérôme Pouiller <jerome.pouiller@xxxxxxxxxx> ERROR: Invalid format: Fixes: 9bca45f3d6924 "staging: wfx: allow to send 802.11 frames" ERROR: Missing Signed-off-by: felipe.negrelliwolter@xxxxxxxxxx -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
