This patch standardizes the inconsistent return values for unsuccessful
XDP transmits by using standardized error codes (-EBUSY or -ENOMEM).

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
---
 v3:
  - remove the fix tag.
  - resend to net-next

 v2:
  - focusing on code clean up per Simon's feedback.

 drivers/net/ethernet/freescale/fec_main.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 42ec6ca3bf03..6a021fe24dfe 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3798,8 +3798,7 @@ static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
 	entries_free = fec_enet_get_free_txdesc_num(txq);
 	if (entries_free < MAX_SKB_FRAGS + 1) {
 		netdev_err(fep->netdev, "NOT enough BD for SG!\n");
-		xdp_return_frame(frame);
-		return NETDEV_TX_BUSY;
+		return -EBUSY;
 	}

 	/* Fill in a Tx ring entry */
@@ -3813,7 +3812,7 @@ static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
 	dma_addr = dma_map_single(&fep->pdev->dev, frame->data,
 				  frame->len, DMA_TO_DEVICE);
 	if (dma_mapping_error(&fep->pdev->dev, dma_addr))
-		return FEC_ENET_XDP_CONSUMED;
+		return -ENOMEM;

 	status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
 	if (fep->bufdesc_ex)
@@ -3869,7 +3868,7 @@ static int fec_enet_xdp_xmit(struct net_device *dev,
 	__netif_tx_lock(nq, cpu);

 	for (i = 0; i < num_frames; i++) {
-		if (fec_enet_txq_xmit_frame(fep, txq, frames[i]) != 0)
+		if (fec_enet_txq_xmit_frame(fep, txq, frames[i]) < 0)
 			break;
 		sent_frames++;
 	}
--
2.34.1

On Thu, 11 May 2023 10:21:15 -0500 Shenwei Wang wrote:
> This patch standardizes the inconsistent return values for unsuccessful
> XDP transmits by using standardized error codes (-EBUSY or -ENOMEM).

Let's split the return code cleanup from the double free fix.
Please post a v4 patch with just the xdp_return_frame() removed,
and none of the other changes. For net (rather than net-next),
with the Fixes tag back.

On Thu, May 11, 2023 at 10:21:15AM -0500, Shenwei Wang wrote:
> This patch standardizes the inconsistent return values for unsuccessful
> XDP transmits by using standardized error codes (-EBUSY or -ENOMEM).
> 
> Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>

Reviewed-by: Simon Horman <simon.horman@corigine.com>