| Message ID | 20231004123039.157112-1-jerome.pouiller@silabs.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] wifi: wfx: fix case where rates are out of order | expand |
Jérôme Pouiller <jerome.pouiller@silabs.com> wrote: > From: Felipe Negrelli Wolter <felipe.negrelliwolter@silabs.com> > > 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 applies rates in descending order, the > workaround is to drop the rate when it higher than its predecessor in > the rate list. Thus [ 4, 5, 3 ] becomes [ 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: 9bca45f3d692 ("staging: wfx: allow to send 802.11 frames") > Tested-by: Olivier Souloumiac <olivier.souloumiac@silabs.com> > Tested-by: Alexandr Suslenko <suslenko.o@ajax.systems> > Reported-by: Alexandr Suslenko <suslenko.o@ajax.systems> > Co-developed-by: Jérôme Pouiller <jerome.pouiller@silabs.com> > Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com> > Signed-off-by: Felipe Negrelli Wolter <felipe.negrelliwolter@silabs.com> Patch applied to wireless-next.git, thanks. ea2274ab0b18 wifi: wfx: fix case where rates are out of order
diff --git a/drivers/net/wireless/silabs/wfx/data_tx.c b/drivers/net/wireless/silabs/wfx/data_tx.c index 6a5e52a96d183..caa22226b01bc 100644 --- a/drivers/net/wireless/silabs/wfx/data_tx.c +++ b/drivers/net/wireless/silabs/wfx/data_tx.c @@ -226,53 +226,40 @@ static u8 wfx_tx_get_link_id(struct wfx_vif *wvif, struct ieee80211_sta *sta, static void wfx_tx_fixup_rates(struct ieee80211_tx_rate *rates) { - int i; - bool finished; + bool has_rate0 = false; + int i, j; - /* Firmware is not able to mix rates with different flags */ - for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { - if (rates[0].flags & IEEE80211_TX_RC_SHORT_GI) - rates[i].flags |= IEEE80211_TX_RC_SHORT_GI; - if (!(rates[0].flags & IEEE80211_TX_RC_SHORT_GI)) + for (i = 1, j = 1; j < IEEE80211_TX_MAX_RATES; j++) { + if (rates[j].idx == -1) + break; + /* The device use the rates in descending order, whatever the request from minstrel. + * We have to trade off here. Most important is to respect the primary rate + * requested by minstrel. So, we drops the entries with rate higher than the + * previous. + */ + if (rates[j].idx >= rates[i - 1].idx) { + rates[i - 1].count += rates[j].count; + rates[i - 1].count = min_t(u16, 15, rates[i - 1].count); + } else { + memcpy(rates + i, rates + j, sizeof(rates[i])); + if (rates[i].idx == 0) + has_rate0 = true; + /* The device apply Short GI only on the first rate */ rates[i].flags &= ~IEEE80211_TX_RC_SHORT_GI; - if (!(rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)) - rates[i].flags &= ~IEEE80211_TX_RC_USE_RTS_CTS; - } - - /* Sort rates and remove duplicates */ - do { - finished = true; - for (i = 0; i < IEEE80211_TX_MAX_RATES - 1; i++) { - if (rates[i + 1].idx == rates[i].idx && - rates[i].idx != -1) { - rates[i].count += rates[i + 1].count; - if (rates[i].count > 15) - rates[i].count = 15; - rates[i + 1].idx = -1; - rates[i + 1].count = 0; - - finished = false; - } - if (rates[i + 1].idx > rates[i].idx) { - swap(rates[i + 1], rates[i]); - finished = false; - } + i++; } - } while (!finished); + } /* Ensure that MCS0 or 1Mbps is present at the end of the retry list */ - for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { - if (rates[i].idx == 0) - break; - if (rates[i].idx == -1) { - rates[i].idx = 0; - rates[i].count = 8; /* == hw->max_rate_tries */ - rates[i].flags = rates[i - 1].flags & IEEE80211_TX_RC_MCS; - break; - } + if (!has_rate0 && i < IEEE80211_TX_MAX_RATES) { + rates[i].idx = 0; + rates[i].count = 8; /* == hw->max_rate_tries */ + rates[i].flags = rates[0].flags & IEEE80211_TX_RC_MCS; + i++; + } + for (; i < IEEE80211_TX_MAX_RATES; i++) { + memset(rates + i, 0, sizeof(rates[i])); + rates[i].idx = -1; } - /* All retries use long GI */ - for (i = 1; i < IEEE80211_TX_MAX_RATES; i++) - rates[i].flags &= ~IEEE80211_TX_RC_SHORT_GI; } static u8 wfx_tx_get_retry_policy_id(struct wfx_vif *wvif, struct ieee80211_tx_info *tx_info)