One option would be to cover this extra condition in enetc_free_tx_ring(),
but now that the ENETC_TX_DOWN exists, we have created a window at
the beginning of enetc_stop() where NAPI can still be scheduled, but
any concurrent enqueue will be blocked. Therefore, enetc_wait_bdrs()
and enetc_disable_tx_bdrs() can be called with NAPI still scheduled,
and it is guaranteed that this will not wait indefinitely, but instead
give us an indication that the pending TX frames have orderly dropped
to zero. Only then should we call napi_disable().
This way, enetc_free_tx_ring() becomes entirely redundant and can be
dropped as part of subsequent cleanup.
The change also refactors enetc_start() so that it looks like the
mirror opposite procedure of enetc_stop().
Fixes: ff58fda09096 ("net: enetc: prioritize ability to go down over packet processing")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
---
v2 changes:
1. Modify the titile and rephrase the commit meesage.
2. Use the new solution as described in the title
v3: no changes.
v4 changes:
1. Modify the title and rephrase the commit message.
---
drivers/net/ethernet/freescale/enetc/enetc.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 52da10f62430..c09370eab319 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -2474,8 +2474,6 @@ 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);
@@ -2484,6 +2482,8 @@ 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);
@@ -2552,6 +2552,10 @@ 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);
@@ -2561,10 +2565,6 @@ 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);
--
2.34.1
