ath9k: improve dma map failure handling

Instead of leaving the buffer without skb and breaking out of the loop
(which could leak the rx buffer), use the common error path.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/recv.c

@@ -1166,6 +1166,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 	u64 tsf = 0;
 	u32 tsf_lower = 0;
 	unsigned long flags;
+	dma_addr_t new_buf_addr;
 
 	if (edma)
 		dma_type = DMA_BIDIRECTIONAL;
@@ -1264,10 +1265,20 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 			goto requeue_drop_frag;
 		}
 
+		/* We will now give hardware our shiny new allocated skb */
+		new_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
+					      common->rx_bufsize, dma_type);
+		if (unlikely(dma_mapping_error(sc->dev, new_buf_addr))) {
+			dev_kfree_skb_any(requeue_skb);
+			goto requeue_drop_frag;
+		}
+
+		bf->bf_mpdu = requeue_skb;
+		bf->bf_buf_addr = new_buf_addr;
+
 		/* Unmap the frame */
 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
-				 common->rx_bufsize,
-				 dma_type);
+				 common->rx_bufsize, dma_type);
 
 		skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
 		if (ah->caps.rx_status_len)
@@ -1277,21 +1288,6 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 			ath9k_rx_skb_postprocess(common, hdr_skb, &rs,
 						 rxs, decrypt_error);
 
-		/* We will now give hardware our shiny new allocated skb */
-		bf->bf_mpdu = requeue_skb;
-		bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
-						 common->rx_bufsize,
-						 dma_type);
-		if (unlikely(dma_mapping_error(sc->dev,
-			  bf->bf_buf_addr))) {
-			dev_kfree_skb_any(requeue_skb);
-			bf->bf_mpdu = NULL;
-			bf->bf_buf_addr = 0;
-			ath_err(common, "dma_mapping_error() on RX\n");
-			ieee80211_rx(hw, skb);
-			break;
-		}
-
 		if (rs.rs_more) {
 			RX_STAT_INC(rx_frags);
 			/*