ath10k: fix dma_mapping_error() handling

commit 5e55e3cb upstream.

The function returns 1 when DMA mapping fails. The
driver would return bogus values and could
possibly confuse itself if DMA failed.

Fixes: 767d34fc ("ath10k: remove DMA mapping wrappers")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/wireless/ath/ath10k/htc.c

@@ -167,8 +167,10 @@ int ath10k_htc_send(struct ath10k_htc *htc,
 
 	skb_cb->paddr = dma_map_single(dev, skb->data, skb->len, DMA_TO_DEVICE);
 	ret = dma_mapping_error(dev, skb_cb->paddr);
-	if (ret)
+	if (ret) {
+		ret = -EIO;
 		goto err_credits;
+	}
 
 	sg_item.transfer_id = ep->eid;
 	sg_item.transfer_context = skb;

drivers/net/wireless/ath/ath10k/htt_tx.c

@@ -345,8 +345,10 @@ int ath10k_htt_mgmt_tx(struct ath10k_htt *htt, struct sk_buff *msdu)
 	skb_cb->paddr = dma_map_single(dev, msdu->data, msdu->len,
 				       DMA_TO_DEVICE);
 	res = dma_mapping_error(dev, skb_cb->paddr);
-	if (res)
+	if (res) {
+		res = -EIO;
 		goto err_free_txdesc;
+	}
 
 	skb_put(txdesc, len);
 	cmd = (struct htt_cmd *)txdesc->data;
@@ -430,8 +432,10 @@ int ath10k_htt_tx(struct ath10k_htt *htt, struct sk_buff *msdu)
 	skb_cb->paddr = dma_map_single(dev, msdu->data, msdu->len,
 				       DMA_TO_DEVICE);
 	res = dma_mapping_error(dev, skb_cb->paddr);
-	if (res)
+	if (res) {
+		res = -EIO;
 		goto err_free_txbuf;
+	}
 
 	if (likely(use_frags)) {
 		frags = skb_cb->htt.txbuf->frags;

drivers/net/wireless/ath/ath10k/pci.c

@@ -1340,8 +1340,10 @@ static int ath10k_pci_hif_exchange_bmi_msg(struct ath10k *ar,
 
 	req_paddr = dma_map_single(ar->dev, treq, req_len, DMA_TO_DEVICE);
 	ret = dma_mapping_error(ar->dev, req_paddr);
-	if (ret)
+	if (ret) {
+		ret = -EIO;
 		goto err_dma;
+	}
 
 	if (resp && resp_len) {
 		tresp = kzalloc(*resp_len, GFP_KERNEL);
@@ -1353,8 +1355,10 @@ static int ath10k_pci_hif_exchange_bmi_msg(struct ath10k *ar,
 		resp_paddr = dma_map_single(ar->dev, tresp, *resp_len,
 					    DMA_FROM_DEVICE);
 		ret = dma_mapping_error(ar->dev, resp_paddr);
-		if (ret)
+		if (ret) {
+			ret = EIO;
 			goto err_req;
+		}
 
 		xfer.wait_for_resp = true;
 		xfer.resp_len = 0;

drivers/net/wireless/ath/ath10k/wmi.c

@@ -1458,6 +1458,7 @@ static void ath10k_wmi_event_host_swba(struct ath10k *ar, struct sk_buff *skb)
 		if (ret) {
 			ath10k_warn("failed to map beacon: %d\n", ret);
 			dev_kfree_skb_any(bcn);
+			ret = -EIO;
 			goto skip;
 		}