mt76: mt7622: fix DMA unmap length

Fix DMA unmap length estimation in mt7615_txp_skb_unmap_hw for mt7622
chipset

Fixes: 6aa4ed79 ("mt76: mt7615: implement DMA support for MT7622")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>

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

@@ -695,7 +695,7 @@ mt7615_txp_skb_unmap_hw(struct mt76_dev *dev, struct mt7615_hw_txp *txp)
 
 		len = le16_to_cpu(ptr->len0);
 		last = len & MT_TXD_LEN_MSDU_LAST;
-		len &= ~MT_TXD_LEN_MSDU_LAST;
+		len &= MT_TXD_LEN_MASK;
 		dma_unmap_single(dev->dev, le32_to_cpu(ptr->buf0), len,
 				 DMA_TO_DEVICE);
 		if (last)
@@ -703,7 +703,7 @@ mt7615_txp_skb_unmap_hw(struct mt76_dev *dev, struct mt7615_hw_txp *txp)
 
 		len = le16_to_cpu(ptr->len1);
 		last = len & MT_TXD_LEN_MSDU_LAST;
-		len &= ~MT_TXD_LEN_MSDU_LAST;
+		len &= MT_TXD_LEN_MASK;
 		dma_unmap_single(dev->dev, le32_to_cpu(ptr->buf1), len,
 				 DMA_TO_DEVICE);
 		if (last)
@@ -1114,8 +1114,8 @@ mt7615_write_hw_txp(struct mt7615_dev *dev, struct mt76_tx_info *tx_info,
 	txp->msdu_id[0] = cpu_to_le16(id | MT_MSDU_ID_VALID);
 
 	for (i = 0; i < nbuf; i++) {
+		u16 len = tx_info->buf[i + 1].len & MT_TXD_LEN_MASK;
 		u32 addr = tx_info->buf[i + 1].addr;
-		u16 len = tx_info->buf[i + 1].len;
 
 		if (i == nbuf - 1)
 			len |= MT_TXD_LEN_MSDU_LAST |

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

@@ -253,6 +253,7 @@ enum tx_phy_bandwidth {
 
 #define MT_MSDU_ID_VALID		BIT(15)
 
+#define MT_TXD_LEN_MASK			GENMASK(11, 0)
 #define MT_TXD_LEN_MSDU_LAST		BIT(14)
 #define MT_TXD_LEN_AMSDU_LAST		BIT(15)