diff mbox series

[v2,net,1/2] net: fec: correct the counting of XDP sent frames

Message ID 20230502220818.691444-1-shenwei.wang@nxp.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [v2,net,1/2] net: fec: correct the counting of XDP sent frames | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 1 maintainers not CCed: bpf@vger.kernel.org
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 37 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Shenwei Wang May 2, 2023, 10:08 p.m. UTC 
In the current xdp_xmit implementation, if any single frame fails to
transmit due to insufficient buffer descriptors, the function nevertheless
reports success in sending all frames. This results in erroneously
indicating that frames were transmitted when in fact they were dropped.

This patch fixes the issue by ensureing the return value properly
indicates the actual number of frames successfully transmitted, rather than
potentially reporting success for all frames when some could not transmit.

Fixes: 6d6b39f180b8 ("net: fec: add initial XDP support")
Signed-off-by: Gagandeep Singh <g.singh@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
---
 v2:
  - only keep the bug fix part of codes according to Horatiu's comments.
  - restructure the functions to avoid the forward declaration.

 drivers/net/ethernet/freescale/fec_main.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--
2.34.1
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 160c1b3525f5..42ec6ca3bf03 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3798,7 +3798,8 @@  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");
-		return NETDEV_TX_OK;
+		xdp_return_frame(frame);
+		return NETDEV_TX_BUSY;
 	}

 	/* Fill in a Tx ring entry */
@@ -3856,6 +3857,7 @@  static int fec_enet_xdp_xmit(struct net_device *dev,
 	struct fec_enet_private *fep = netdev_priv(dev);
 	struct fec_enet_priv_tx_q *txq;
 	int cpu = smp_processor_id();
+	unsigned int sent_frames = 0;
 	struct netdev_queue *nq;
 	unsigned int queue;
 	int i;
@@ -3866,8 +3868,11 @@  static int fec_enet_xdp_xmit(struct net_device *dev,

 	__netif_tx_lock(nq, cpu);

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

 	/* Make sure the update to bdp and tx_skbuff are performed. */
 	wmb();
@@ -3877,7 +3882,7 @@  static int fec_enet_xdp_xmit(struct net_device *dev,

 	__netif_tx_unlock(nq);

-	return num_frames;
+	return sent_frames;
 }

 static const struct net_device_ops fec_netdev_ops = {