RE: [PATCH net-next 07/11] net: fec: use switch statement to check the type of tx_buf

On Tue, Jan 13, 2026 at 11:29:35AM +0800, Wei Fang wrote:

quoted

The tx_buf has three types: FEC_TXBUF_T_SKB, FEC_TXBUF_T_XDP_NDO and
FEC_TXBUF_T_XDP_TX. Currently, the driver uses 'if...else...'
statements to check the type and perform the corresponding processing.
This is very detrimental to future expansion. For example, if new
types are added to support XDP zero copy in the future, continuing to use

'if...else...'

quoted

would be a very bad coding style. So the 'if...else...' statements in
the current driver are replaced with switch statements to support XDP
zero copy in the future.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 drivers/net/ethernet/freescale/fec_main.c | 167
+++++++++++-----------
 1 file changed, 82 insertions(+), 85 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c

b/drivers/net/ethernet/freescale/fec_main.c
index f3e93598a27c..3bd89d7f105b 100644

--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c

@@ -1023,33 +1023,33 @@ static void fec_enet_bd_init(struct net_device

*dev)

quoted

 		txq->bd.cur = bdp;

 		for (i = 0; i < txq->bd.ring_size; i++) {
+			dma_addr_t dma = fec32_to_cpu(bdp->cbd_bufaddr);
+			struct page *page;
+
 			/* Initialize the BD for every fragment in the page. */
 			bdp->cbd_sc = cpu_to_fec16(0);
-			if (txq->tx_buf[i].type == FEC_TXBUF_T_SKB) {
-				if (bdp->cbd_bufaddr &&
-				    !IS_TSO_HEADER(txq,

fec32_to_cpu(bdp->cbd_bufaddr)))

quoted

-					dma_unmap_single(&fep->pdev->dev,
-							 fec32_to_cpu(bdp->cbd_bufaddr),
-							 fec16_to_cpu(bdp->cbd_datlen),
-							 DMA_TO_DEVICE);
-				if (txq->tx_buf[i].buf_p)
-					dev_kfree_skb_any(txq->tx_buf[i].buf_p);
-			} else if (txq->tx_buf[i].type == FEC_TXBUF_T_XDP_NDO) {
-				if (bdp->cbd_bufaddr)
-					dma_unmap_single(&fep->pdev->dev,
-							 fec32_to_cpu(bdp->cbd_bufaddr),
+			switch (txq->tx_buf[i].type) {
+			case FEC_TXBUF_T_SKB:
+				if (dma && !IS_TSO_HEADER(txq, dma))
+					dma_unmap_single(&fep->pdev->dev, dma,
 							 fec16_to_cpu(bdp->cbd_datlen),
 							 DMA_TO_DEVICE);

-				if (txq->tx_buf[i].buf_p)
-					xdp_return_frame(txq->tx_buf[i].buf_p);
-			} else {
-				struct page *page = txq->tx_buf[i].buf_p;
-
-				if (page)
-					page_pool_put_page(pp_page_to_nmdesc(page)->pp,
-							   page, 0,
-							   false);
+				dev_kfree_skb_any(txq->tx_buf[i].buf_p);
+				break;
+			case FEC_TXBUF_T_XDP_NDO:
+				dma_unmap_single(&fep->pdev->dev, dma,
+						 fec16_to_cpu(bdp->cbd_datlen),
+						 DMA_TO_DEVICE);
+				xdp_return_frame(txq->tx_buf[i].buf_p);

look like logic is not exactly same as original one

if (txq->tx_buf[i].type == FEC_TXBUF_T_XDP_NDO) {
	if (bdp->cbd_bufaddr)
		...

Yes, I did some cleanup as well, because the case of NULL pointer is
always false.