e1000/e1000e/igb/igbvf/ixgb/ixgbe: Fix tests of unsigned in *_tx_map()

The variable count and i are unsigned so the (<|>=)0 tests do not work.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/e1000/e1000_main.c

@@ -2802,13 +2802,13 @@ static int e1000_tx_map(struct e1000_adapter *adapter,
 dma_error:
 	dev_err(&pdev->dev, "TX DMA map failed\n");
 	buffer_info->dma = 0;
-	count--;
-
-	while (count >= 0) {
+	if (count)
 		count--;
-		i--;
-		if (i < 0)
+
+	while (count--) {
+		if (i==0)
 			i += tx_ring->count;
+		i--;
 		buffer_info = &tx_ring->buffer_info[i];
 		e1000_unmap_and_free_tx_resource(adapter, buffer_info);
 	}

drivers/net/e1000e/netdev.c

@@ -3962,13 +3962,13 @@ static int e1000_tx_map(struct e1000_adapter *adapter,
 dma_error:
 	dev_err(&pdev->dev, "TX DMA map failed\n");
 	buffer_info->dma = 0;
-	count--;
-
-	while (count >= 0) {
+	if (count)
 		count--;
-		i--;
-		if (i < 0)
+
+	while (count--) {
+		if (i==0)
 			i += tx_ring->count;
+		i--;
 		buffer_info = &tx_ring->buffer_info[i];
 		e1000_put_txbuf(adapter, buffer_info);;
 	}

drivers/net/igbvf/netdev.c

@@ -2163,14 +2163,14 @@ dma_error:
 	buffer_info->length = 0;
 	buffer_info->next_to_watch = 0;
 	buffer_info->mapped_as_page = false;
-	count--;
+	if (count)
+		count--;
 
 	/* clear timestamp and dma mappings for remaining portion of packet */
-	while (count >= 0) {
-		count--;
-		i--;
-		if (i < 0)
+	while (count--) {
+		if (i==0)
 			i += tx_ring->count;
+		i--;
 		buffer_info = &tx_ring->buffer_info[i];
 		igbvf_put_txbuf(adapter, buffer_info);
 	}

drivers/net/ixgb/ixgb_main.c

@@ -1363,13 +1363,13 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb,
 dma_error:
 	dev_err(&pdev->dev, "TX DMA map failed\n");
 	buffer_info->dma = 0;
-	count--;
-
-	while (count >= 0) {
+	if (count)
 		count--;
-		i--;
-		if (i < 0)
+
+	while (count--) {
+		if (i==0)
 			i += tx_ring->count;
+		i--;
 		buffer_info = &tx_ring->buffer_info[i];
 		ixgb_unmap_and_free_tx_resource(adapter, buffer_info);
 	}

drivers/net/ixgbe/ixgbe_main.c

@@ -5167,14 +5167,14 @@ dma_error:
 	tx_buffer_info->dma = 0;
 	tx_buffer_info->time_stamp = 0;
 	tx_buffer_info->next_to_watch = 0;
-	count--;
+	if (count)
+		count--;
 
 	/* clear timestamp and dma mappings for remaining portion of packet */
-	while (count >= 0) {
-		count--;
-		i--;
-		if (i < 0)
+	while (count--) {
+		if (i==0)
 			i += tx_ring->count;
+		i--;
 		tx_buffer_info = &tx_ring->tx_buffer_info[i];
 		ixgbe_unmap_and_free_tx_resource(adapter, tx_buffer_info);
 	}