sfc: push partner queue for skb->xmit_more
When the IP stack passes SKBs the sfc driver puts them in 2 different TX
queues (called partners), one for checksummed and one for not checksummed.
If the SKB has xmit_more set the driver will delay pushing the work to the
NIC.
When later it does decide to push the buffers this patch ensures it also
pushes the partner queue, if that also has any delayed work. Before this
fix the work in the partner queue would be left for a long time and cause
a netdev watchdog.
Fixes: 70b33fb ("sfc: add support for skb->xmit_more")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Martin Habets <mhabets@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index ff649eb..286cc6b 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -1849,7 +1849,9 @@
unsigned int write_ptr;
efx_qword_t *txd;
- BUG_ON(tx_queue->write_count == tx_queue->insert_count);
+ tx_queue->xmit_more_available = false;
+ if (unlikely(tx_queue->write_count == tx_queue->insert_count))
+ return;
do {
write_ptr = tx_queue->write_count & tx_queue->ptr_mask;
diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c
index f08266f..5a1c5a8 100644
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/drivers/net/ethernet/sfc/farch.c
@@ -321,7 +321,9 @@
unsigned write_ptr;
unsigned old_write_count = tx_queue->write_count;
- BUG_ON(tx_queue->write_count == tx_queue->insert_count);
+ tx_queue->xmit_more_available = false;
+ if (unlikely(tx_queue->write_count == tx_queue->insert_count))
+ return;
do {
write_ptr = tx_queue->write_count & tx_queue->ptr_mask;
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index c530e1c..24038ef 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -219,6 +219,7 @@
* @tso_packets: Number of packets via the TSO xmit path
* @pushes: Number of times the TX push feature has been used
* @pio_packets: Number of times the TX PIO feature has been used
+ * @xmit_more_available: Are any packets waiting to be pushed to the NIC
* @empty_read_count: If the completion path has seen the queue as empty
* and the transmission path has not yet checked this, the value of
* @read_count bitwise-added to %EFX_EMPTY_COUNT_VALID; otherwise 0.
@@ -253,6 +254,7 @@
unsigned int tso_packets;
unsigned int pushes;
unsigned int pio_packets;
+ bool xmit_more_available;
/* Statistics to supplement MAC stats */
unsigned long tx_packets;
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 1833a01..67f6afa 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -431,8 +431,20 @@
efx_tx_maybe_stop_queue(tx_queue);
/* Pass off to hardware */
- if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq))
+ if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {
+ struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);
+
+ /* There could be packets left on the partner queue if those
+ * SKBs had skb->xmit_more set. If we do not push those they
+ * could be left for a long time and cause a netdev watchdog.
+ */
+ if (txq2->xmit_more_available)
+ efx_nic_push_buffers(txq2);
+
efx_nic_push_buffers(tx_queue);
+ } else {
+ tx_queue->xmit_more_available = skb->xmit_more;
+ }
tx_queue->tx_packets++;
@@ -722,6 +734,7 @@
tx_queue->read_count = 0;
tx_queue->old_read_count = 0;
tx_queue->empty_read_count = 0 | EFX_EMPTY_COUNT_VALID;
+ tx_queue->xmit_more_available = false;
/* Set up TX descriptor ring */
efx_nic_init_tx(tx_queue);
@@ -747,6 +760,7 @@
++tx_queue->read_count;
}
+ tx_queue->xmit_more_available = false;
netdev_tx_reset_queue(tx_queue->core_txq);
}
@@ -1302,8 +1316,20 @@
efx_tx_maybe_stop_queue(tx_queue);
/* Pass off to hardware */
- if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq))
+ if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {
+ struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);
+
+ /* There could be packets left on the partner queue if those
+ * SKBs had skb->xmit_more set. If we do not push those they
+ * could be left for a long time and cause a netdev watchdog.
+ */
+ if (txq2->xmit_more_available)
+ efx_nic_push_buffers(txq2);
+
efx_nic_push_buffers(tx_queue);
+ } else {
+ tx_queue->xmit_more_available = skb->xmit_more;
+ }
tx_queue->tso_bursts++;
return NETDEV_TX_OK;