mt76: mt7915: 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: Felix Fietkau <nbd@nbd.name>

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

@@ -93,6 +93,7 @@ mt7915_init_wiphy(struct ieee80211_hw *hw)
 	hw->queues = 4;
 	hw->max_rx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
 	hw->max_tx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
+	hw->netdev_features = NETIF_F_RXCSUM;
 
 	phy->slottime = 9;
 

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

@@ -317,10 +317,12 @@ int mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
 	__le32 *rxd = (__le32 *)skb->data;
 	__le32 *rxv = NULL;
 	u32 mode = 0;
+	u32 rxd0 = le32_to_cpu(rxd[0]);
 	u32 rxd1 = le32_to_cpu(rxd[1]);
 	u32 rxd2 = le32_to_cpu(rxd[2]);
 	u32 rxd3 = le32_to_cpu(rxd[3]);
 	u32 rxd4 = le32_to_cpu(rxd[4]);
+	u32 csum_mask = MT_RXD0_NORMAL_IP_SUM | MT_RXD0_NORMAL_UDP_TCP_SUM;
 	bool unicast, insert_ccmp_hdr = false;
 	u8 remove_pad, amsdu_info;
 	int i, idx;
@@ -366,6 +368,9 @@ int mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
 	if (!sband->channels)
 		return -EINVAL;
 
+	if ((rxd0 & csum_mask) == csum_mask)
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
 	if (rxd1 & MT_RXD1_NORMAL_FCS_ERR)
 		status->flag |= RX_FLAG_FAILED_FCS_CRC;