Revert "mt76: use IEEE80211_OFFLOAD_ENCAP_ENABLED instead of MT_DRV_AMSDU_OFFLOAD"

This reverts commit f17f4864 and adds the
MT_DRV_AMSDU_OFFLOAD flag for MT7921 USB/SDIO

The reverted commit significantly decreases performance when running
a test where two MT7915 radios have 16 station vdevs each, configured
for AC mode, and transmitting UDP traffic to AP.
Co-developed-by: Felix Fietkau <nbd@nbd.name>
Reported-by: Carson Vandegriffe <carson.vandegriffe@candelatech.com>
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mac80211.c

@@ -443,8 +443,12 @@ mt76_phy_init(struct mt76_phy *phy, struct ieee80211_hw *hw)
 	ieee80211_hw_set(hw, SUPPORTS_CLONED_SKBS);
 	ieee80211_hw_set(hw, SUPPORTS_AMSDU_IN_AMPDU);
 	ieee80211_hw_set(hw, SUPPORTS_REORDERING_BUFFER);
-	ieee80211_hw_set(hw, TX_AMSDU);
-	ieee80211_hw_set(hw, TX_FRAG_LIST);
+
+	if (!(dev->drv->drv_flags & MT_DRV_AMSDU_OFFLOAD)) {
+		ieee80211_hw_set(hw, TX_AMSDU);
+		ieee80211_hw_set(hw, TX_FRAG_LIST);
+	}
+
 	ieee80211_hw_set(hw, MFP_CAPABLE);
 	ieee80211_hw_set(hw, AP_LINK_PS);
 	ieee80211_hw_set(hw, REPORTS_TX_ACK_STATUS);

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -415,6 +415,7 @@ struct mt76_hw_cap {
 #define MT_DRV_SW_RX_AIRTIME		BIT(2)
 #define MT_DRV_RX_DMA_HDR		BIT(3)
 #define MT_DRV_HW_MGMT_TXQ		BIT(4)
+#define MT_DRV_AMSDU_OFFLOAD		BIT(5)
 
 struct mt76_driver_ops {
 	u32 drv_flags;

drivers/net/wireless/mediatek/mt76/mt7915/mmio.c

@@ -781,7 +781,8 @@ struct mt7915_dev *mt7915_mmio_probe(struct device *pdev,
 	static const struct mt76_driver_ops drv_ops = {
 		/* txwi_size = txd size + txp size */
 		.txwi_size = MT_TXD_SIZE + sizeof(struct mt76_connac_fw_txp),
-		.drv_flags = MT_DRV_TXWI_NO_FREE | MT_DRV_HW_MGMT_TXQ,
+		.drv_flags = MT_DRV_TXWI_NO_FREE | MT_DRV_HW_MGMT_TXQ |
+			     MT_DRV_AMSDU_OFFLOAD,
 		.survey_flags = SURVEY_INFO_TIME_TX |
 				SURVEY_INFO_TIME_RX |
 				SURVEY_INFO_TIME_BSS_RX,

drivers/net/wireless/mediatek/mt76/mt7921/pci.c

@@ -228,7 +228,8 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
 	static const struct mt76_driver_ops drv_ops = {
 		/* txwi_size = txd size + txp size */
 		.txwi_size = MT_TXD_SIZE + sizeof(struct mt76_connac_hw_txp),
-		.drv_flags = MT_DRV_TXWI_NO_FREE | MT_DRV_HW_MGMT_TXQ,
+		.drv_flags = MT_DRV_TXWI_NO_FREE | MT_DRV_HW_MGMT_TXQ |
+			     MT_DRV_AMSDU_OFFLOAD,
 		.survey_flags = SURVEY_INFO_TIME_TX |
 				SURVEY_INFO_TIME_RX |
 				SURVEY_INFO_TIME_BSS_RX,

drivers/net/wireless/mediatek/mt76/mt7921/sdio.c

@@ -89,6 +89,7 @@ static int mt7921s_probe(struct sdio_func *func,
 {
 	static const struct mt76_driver_ops drv_ops = {
 		.txwi_size = MT_SDIO_TXD_SIZE,
+		.drv_flags = MT_DRV_AMSDU_OFFLOAD,
 		.survey_flags = SURVEY_INFO_TIME_TX |
 				SURVEY_INFO_TIME_RX |
 				SURVEY_INFO_TIME_BSS_RX,

drivers/net/wireless/mediatek/mt76/mt7921/usb.c

@@ -170,7 +170,8 @@ static int mt7921u_probe(struct usb_interface *usb_intf,
 {
 	static const struct mt76_driver_ops drv_ops = {
 		.txwi_size = MT_SDIO_TXD_SIZE,
-		.drv_flags = MT_DRV_RX_DMA_HDR | MT_DRV_HW_MGMT_TXQ,
+		.drv_flags = MT_DRV_RX_DMA_HDR | MT_DRV_HW_MGMT_TXQ |
+			     MT_DRV_AMSDU_OFFLOAD,
 		.survey_flags = SURVEY_INFO_TIME_TX |
 				SURVEY_INFO_TIME_RX |
 				SURVEY_INFO_TIME_BSS_RX,