From: Théo Lebrun <theo.lebrun@bootlin.com>
Date: Tue, 14 Oct 2025 15:25:13 +0000 (+0200)
Subject: net: macb: drop `entry` local variable in macb_tx_map()
X-Git-Tag: v6.19-rc1~170^2~364^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=027202adf07952d9b4d7a3199fe1014a537e7a81;p=thirdparty%2Flinux.git

net: macb: drop `entry` local variable in macb_tx_map()

The pattern:
   entry = macb_tx_ring_wrap(bp, i);
   tx_skb = &queue->tx_skb[entry];
is the exact definition of:
   macb_tx_skb(queue, i);

The pattern:
   entry = macb_tx_ring_wrap(bp, i);
   desc = macb_tx_desc(queue, entry);
is redundant because macb_tx_desc() calls macb_tx_ring_wrap().

One explicit call to macb_tx_ring_wrap() is still required for checking
if it is the last buffer (TX_WRAP case).

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://patch.msgid.link/20251014-macb-cleanup-v1-12-31cd266e22cd@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 6c6bc6aa23c71..08e541d8f8e68 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -1989,7 +1989,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 				unsigned int hdrlen)
 {
 	dma_addr_t mapping;
-	unsigned int len, entry, i, tx_head = queue->tx_head;
+	unsigned int len, i, tx_head = queue->tx_head;
 	struct macb_tx_skb *tx_skb = NULL;
 	struct macb_dma_desc *desc;
 	unsigned int offset, size, count = 0;
@@ -2015,8 +2015,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 
 	offset = 0;
 	while (len) {
-		entry = macb_tx_ring_wrap(bp, tx_head);
-		tx_skb = &queue->tx_skb[entry];
+		tx_skb = macb_tx_skb(queue, tx_head);
 
 		mapping = dma_map_single(&bp->pdev->dev,
 					 skb->data + offset,
@@ -2046,8 +2045,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 		offset = 0;
 		while (len) {
 			size = umin(len, bp->max_tx_length);
-			entry = macb_tx_ring_wrap(bp, tx_head);
-			tx_skb = &queue->tx_skb[entry];
+			tx_skb = macb_tx_skb(queue, tx_head);
 
 			mapping = skb_frag_dma_map(&bp->pdev->dev, frag,
 						   offset, size, DMA_TO_DEVICE);
@@ -2084,9 +2082,8 @@ static unsigned int macb_tx_map(struct macb *bp,
 	 * to set the end of TX queue
 	 */
 	i = tx_head;
-	entry = macb_tx_ring_wrap(bp, i);
 	ctrl = MACB_BIT(TX_USED);
-	desc = macb_tx_desc(queue, entry);
+	desc = macb_tx_desc(queue, i);
 	desc->ctrl = ctrl;
 
 	if (lso_ctrl) {
@@ -2106,16 +2103,15 @@ static unsigned int macb_tx_map(struct macb *bp,
 
 	do {
 		i--;
-		entry = macb_tx_ring_wrap(bp, i);
-		tx_skb = &queue->tx_skb[entry];
-		desc = macb_tx_desc(queue, entry);
+		tx_skb = macb_tx_skb(queue, i);
+		desc = macb_tx_desc(queue, i);
 
 		ctrl = (u32)tx_skb->size;
 		if (eof) {
 			ctrl |= MACB_BIT(TX_LAST);
 			eof = 0;
 		}
-		if (unlikely(entry == (bp->tx_ring_size - 1)))
+		if (unlikely(macb_tx_ring_wrap(bp, i) == bp->tx_ring_size - 1))
 			ctrl |= MACB_BIT(TX_WRAP);
 
 		/* First descriptor is header descriptor */