qlcnic: fix race in tx stop queue
There is a race between netif_stop_queue and netif_stopped_queue
check. So check once again if buffers are available to avoid race.
With above logic we can also get rid of tx lock in process_cmd_ring.
Signed-off-by: Rajesh K Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/qlcnic/qlcnic_main.c b/drivers/net/qlcnic/qlcnic_main.c
index 06d2dfd..655bccd 100644
--- a/drivers/net/qlcnic/qlcnic_main.c
+++ b/drivers/net/qlcnic/qlcnic_main.c
@@ -132,12 +132,6 @@
struct qlcnic_host_tx_ring *tx_ring)
{
writel(tx_ring->producer, tx_ring->crb_cmd_producer);
-
- if (qlcnic_tx_avail(tx_ring) <= TX_STOP_THRESH) {
- netif_stop_queue(adapter->netdev);
- smp_mb();
- adapter->stats.xmit_off++;
- }
}
static const u32 msi_tgt_status[8] = {
@@ -1137,7 +1131,7 @@
adapter->max_mc_count = 38;
netdev->netdev_ops = &qlcnic_netdev_ops;
- netdev->watchdog_timeo = 2*HZ;
+ netdev->watchdog_timeo = 5*HZ;
qlcnic_change_mtu(netdev, netdev->mtu);
@@ -1709,10 +1703,15 @@
/* 4 fragments per cmd des */
no_of_desc = (frag_count + 3) >> 2;
- if (unlikely(no_of_desc + 2 > qlcnic_tx_avail(tx_ring))) {
+ if (unlikely(qlcnic_tx_avail(tx_ring) <= TX_STOP_THRESH)) {
netif_stop_queue(netdev);
- adapter->stats.xmit_off++;
- return NETDEV_TX_BUSY;
+ smp_mb();
+ if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH)
+ netif_start_queue(netdev);
+ else {
+ adapter->stats.xmit_off++;
+ return NETDEV_TX_BUSY;
+ }
}
producer = tx_ring->producer;
@@ -2018,14 +2017,12 @@
smp_mb();
if (netif_queue_stopped(netdev) && netif_carrier_ok(netdev)) {
- __netif_tx_lock(tx_ring->txq, smp_processor_id());
if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH) {
netif_wake_queue(netdev);
- adapter->tx_timeo_cnt = 0;
adapter->stats.xmit_on++;
}
- __netif_tx_unlock(tx_ring->txq);
}
+ adapter->tx_timeo_cnt = 0;
}
/*
* If everything is freed up to consumer then check if the ring is full