mt76: mt7615: add rx checksum offload support

Set skb->ip_summed to CHECKSUM_UNNECESSARY if the hardware has validated
the IP and TCP/UDP checksum
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7615/init.c

@@ -329,6 +329,7 @@ mt7615_init_wiphy(struct ieee80211_hw *hw)
 	hw->max_rates = 3;
 	hw->max_report_rates = 7;
 	hw->max_rate_tries = 11;
+	hw->netdev_features = NETIF_F_RXCSUM;
 
 	phy->slottime = 9;
 

drivers/net/wireless/mediatek/mt76/mt7615/mac.c

@@ -234,6 +234,7 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb)
 	u32 rxd0 = le32_to_cpu(rxd[0]);
 	u32 rxd1 = le32_to_cpu(rxd[1]);
 	u32 rxd2 = le32_to_cpu(rxd[2]);
+	u32 csum_mask = MT_RXD0_NORMAL_IP_SUM | MT_RXD0_NORMAL_UDP_TCP_SUM;
 	__le32 rxd12 = rxd[12];
 	bool unicast, remove_pad, insert_ccmp_hdr = false;
 	int phy_idx;
@@ -271,6 +272,9 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb)
 		spin_unlock_bh(&dev->sta_poll_lock);
 	}
 
+	if ((rxd0 & csum_mask) == csum_mask)
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
 	if (rxd2 & MT_RXD2_NORMAL_FCS_ERR)
 		status->flag |= RX_FLAG_FAILED_FCS_CRC;