@@ -2468,8 +2468,6 @@ void enetc_start(struct net_device *ndev)
enetc_setup_interrupts(priv);
- enetc_enable_tx_bdrs(priv);
-
for (i = 0; i < priv->bdr_int_num; i++) {
int irq = pci_irq_vector(priv->si->pdev,
ENETC_BDR_INT_BASE_IDX + i);
@@ -2478,6 +2476,8 @@ void enetc_start(struct net_device *ndev)
enable_irq(irq);
}
+ enetc_enable_tx_bdrs(priv);
+
enetc_enable_rx_bdrs(priv);
netif_tx_start_all_queues(ndev);
@@ -2546,6 +2546,10 @@ void enetc_stop(struct net_device *ndev)
enetc_disable_rx_bdrs(priv);
+ enetc_wait_bdrs(priv);
+
+ enetc_disable_tx_bdrs(priv);
+
for (i = 0; i < priv->bdr_int_num; i++) {
int irq = pci_irq_vector(priv->si->pdev,
ENETC_BDR_INT_BASE_IDX + i);
@@ -2555,10 +2559,6 @@ void enetc_stop(struct net_device *ndev)
napi_disable(&priv->int_vector[i]->napi);
}
- enetc_wait_bdrs(priv);
-
- enetc_disable_tx_bdrs(priv);
-
enetc_clear_interrupts(priv);
}
EXPORT_SYMBOL_GPL(enetc_stop);
When running "xdp-bench tx eno0" to test the XDP_TX feature of ENETC on LS1028A, it was found that if the command was re-run multiple times, Rx could not receive the frames, and the result of xdo-bench showed that the rx rate was 0. root@ls1028ardb:~# ./xdp-bench tx eno0 Hairpinning (XDP_TX) packets on eno0 (ifindex 3; driver fsl_enetc) Summary 2046 rx/s 0 err,drop/s Summary 0 rx/s 0 err,drop/s Summary 0 rx/s 0 err,drop/s Summary 0 rx/s 0 err,drop/s By observing the Rx PIR and CIR registers, we found that CIR is always equal to 0x7FF and PIR is always 0x7FE, which means that the Rx ring is full and can no longer accommodate other Rx frames. Therefore, we can conclude that the problem is caused by the Rx BD ring not being cleaned up. Further analysis of the code revealed that the Rx BD ring will only be cleaned if the "cleaned_cnt > xdp_tx_in_flight" condition is met. Therefore, some debug logs were added to the driver and the current values of cleaned_cnt and xdp_tx_in_flight were printed when the Rx BD ring was full. The logs are as follows. [ 178.762419] [XDP TX] >> cleaned_cnt:1728, xdp_tx_in_flight:2140 [ 178.771387] [XDP TX] >> cleaned_cnt:1941, xdp_tx_in_flight:2110 [ 178.776058] [XDP TX] >> cleaned_cnt:1792, xdp_tx_in_flight:2110 From the results, we can see that the max value of xdp_tx_in_flight has reached 2140. However, the size of the Rx BD ring is only 2048. This is incredible, so we checked the code again and found that xdp_tx_in_flight did not drop to 0 when the bpf program was uninstalled and it was not reset when the bfp program was installed again. The root cause is that the IRQ is disabled too early in enetc_stop(), resulting in enetc_recycle_xdp_tx_buff() not being called, therefore, xdp_tx_in_flight is not cleared. Fixes: ff58fda09096 ("net: enetc: prioritize ability to go down over packet processing") Cc: stable@vger.kernel.org Signed-off-by: Wei Fang <wei.fang@nxp.com> --- v2 changes: 1. Modify the titile and rephrase the commit meesage. 2. Use the new solution as described in the title --- drivers/net/ethernet/freescale/enetc/enetc.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)