> When the hardware falls back to lower rates for a transmit attempt, only the > first status report will show the number of retries correctly. The frames > that follow will report the correct final rate, but number of retries set to 0. > This can cause the rate control module to vastly underestimate the number of > retransmissions per rate. > > To fix this, we need to keep track of the initial requested tx rate per packet > and pass it to the status information. > For frames with tx status requested, this is simple: use the rate configured > in info->control.rates[0] as reference. > For no-skb tx status information, we have to encode the requested tx rate in > the packet id (and make it possible to distinguish it from real packet ids). > > To do that, reduce the packet id field size by one bit, and use that bit to > indicate packet id vs rate. > > This change also improves reporting by filling the status rate array with > rates from first rate to final rate, taking the same steps as the hardware > fallback table. This matters in corner cases like MCS8 on HT, where the > fallback target is MCS0, not MCS7. > [...] > diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_txrx.c b/drivers/net/wireless/mediatek/mt76/mt76x02_txrx.c > index cf7abd9b7d2e..95c73049a68b 100644 > --- a/drivers/net/wireless/mediatek/mt76/mt76x02_txrx.c > +++ b/drivers/net/wireless/mediatek/mt76/mt76x02_txrx.c > @@ -164,9 +164,14 @@ int mt76x02_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr, > mt76x02_mac_write_txwi(dev, txwi, tx_info->skb, wcid, sta, len); > > pid = mt76_tx_status_skb_add(mdev, wcid, tx_info->skb); > + > + /* encode packet rate for no-skb packet id to fix up status reporting */ > + if (pid == MT_PACKET_ID_NO_SKB) > + pid = MT_PACKET_ID_HAS_RATE | (txwi->rate & MT_RXWI_RATE_INDEX); I guess here we should do: pid = MT_PACKET_ID_HAS_RATE | (le16_to_cpu(txwi->rate) & MT_RXWI_RATE_INDEX); > + > txwi->pktid = pid; > > - if (pid >= MT_PACKET_ID_FIRST) > + if (mt76_is_skb_pktid(pid)) > qsel = MT_QSEL_MGMT; > > tx_info->info = FIELD_PREP(MT_TXD_INFO_QSEL, qsel) | > diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c > index 6b89f7eab26c..2436f14ca24a 100644 > --- a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c > +++ b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_core.c > @@ -89,9 +89,14 @@ int mt76x02u_tx_prepare_skb(struct mt76_dev *mdev, void *data, > skb_push(tx_info->skb, sizeof(*txwi)); > > pid = mt76_tx_status_skb_add(mdev, wcid, tx_info->skb); > + > + /* encode packet rate for no-skb packet id to fix up status reporting */ > + if (pid == MT_PACKET_ID_NO_SKB) > + pid = MT_PACKET_ID_HAS_RATE | (txwi->rate & MT_RXWI_RATE_INDEX); same here Regards, Lorenzo > + > txwi->pktid = pid; > > - if (pid >= MT_PACKET_ID_FIRST || ep == MT_EP_OUT_HCCA) > + if (mt76_is_skb_pktid(pid) || ep == MT_EP_OUT_HCCA) > qsel = MT_QSEL_MGMT; > else > qsel = MT_QSEL_EDCA; > -- > 2.17.0 >
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