wil6210: Fix TSO overflow handling

When Tx ring full is encountered with TSO,
printout of "DMA error" was wrongly printed.

In addition, in case of Tx ring full return
proper error code so that NETDEV_TX_BUSY is
returned to network stack in order not to
drop the packets and retry transmission of the
packets when ring is emptied.

Signed-off-by: Hamad Kadmany <qca_hkadmany@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/wil6210/txrx.c

@@ -1242,6 +1242,7 @@ static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
 	int tcp_hdr_len;
 	int skb_net_hdr_len;
 	int gso_type;
+	int rc = -EINVAL;
 
 	wil_dbg_txrx(wil, "%s() %d bytes to vring %d\n",
 		     __func__, skb->len, vring_index);
@@ -1333,8 +1334,9 @@ static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
 				     len, rem_data, descs_used);
 
 			if (descs_used == avail)  {
-				wil_err(wil, "TSO: ring overflow\n");
-				goto dma_error;
+				wil_err_ratelimited(wil, "TSO: ring overflow\n");
+				rc = -ENOMEM;
+				goto mem_error;
 			}
 
 			lenmss = min_t(int, rem_data, len);
@@ -1356,8 +1358,10 @@ static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
 				headlen -= lenmss;
 			}
 
-			if (unlikely(dma_mapping_error(dev, pa)))
-				goto dma_error;
+			if (unlikely(dma_mapping_error(dev, pa))) {
+				wil_err(wil, "TSO: DMA map page error\n");
+				goto mem_error;
+			}
 
 			_desc = &vring->va[i].tx;
 
@@ -1456,8 +1460,8 @@ static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
 	}
 
 	/* advance swhead */
-	wil_dbg_txrx(wil, "TSO: Tx swhead %d -> %d\n", swhead, vring->swhead);
 	wil_vring_advance_head(vring, descs_used);
+	wil_dbg_txrx(wil, "TSO: Tx swhead %d -> %d\n", swhead, vring->swhead);
 
 	/* make sure all writes to descriptors (shared memory) are done before
 	 * committing them to HW
@@ -1467,8 +1471,7 @@ static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
 	wil_w(wil, vring->hwtail, vring->swhead);
 	return 0;
 
-dma_error:
-	wil_err(wil, "TSO: DMA map page error\n");
+mem_error:
 	while (descs_used > 0) {
 		struct wil_ctx *ctx;
 
@@ -1479,14 +1482,11 @@ static int __wil_tx_vring_tso(struct wil6210_priv *wil, struct vring *vring,
 		_desc->dma.status = TX_DMA_STATUS_DU;
 		ctx = &vring->ctx[i];
 		wil_txdesc_unmap(dev, d, ctx);
-		if (ctx->skb)
-			dev_kfree_skb_any(ctx->skb);
 		memset(ctx, 0, sizeof(*ctx));
 		descs_used--;
 	}
-
 err_exit:
-	return -EINVAL;
+	return rc;
 }
 
 static int __wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
@@ -1562,8 +1562,11 @@ static int __wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
 		_d = &vring->va[i].tx;
 		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
 				      DMA_TO_DEVICE);
-		if (unlikely(dma_mapping_error(dev, pa)))
+		if (unlikely(dma_mapping_error(dev, pa))) {
+			wil_err(wil, "Tx[%2d] failed to map fragment\n",
+				vring_index);
 			goto dma_error;
+		}
 		vring->ctx[i].mapped_as = wil_mapped_as_page;
 		wil_tx_desc_map(d, pa, len, vring_index);
 		/* no need to check return code -
@@ -1623,9 +1626,6 @@ static int __wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
 		_d->dma.status = TX_DMA_STATUS_DU;
 		wil_txdesc_unmap(dev, d, ctx);
 
-		if (ctx->skb)
-			dev_kfree_skb_any(ctx->skb);
-
 		memset(ctx, 0, sizeof(*ctx));
 	}