@@ -731,14 +731,9 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
smp_mb();
if (unlikely(netif_tx_queue_stopped(txq)) &&
- (bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh)) {
- __netif_tx_lock(txq, smp_processor_id());
- if (netif_tx_queue_stopped(txq) &&
- bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh &&
- txr->dev_state != BNXT_DEV_STATE_CLOSING)
- netif_tx_wake_queue(txq);
- __netif_tx_unlock(txq);
- }
+ bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh &&
+ READ_ONCE(txr->dev_state) != BNXT_DEV_STATE_CLOSING)
+ netif_tx_wake_queue(txq);
}
static struct page *__bnxt_alloc_rx_page(struct bnxt *bp, dma_addr_t *mapping,
@@ -9264,9 +9259,11 @@ void bnxt_tx_disable(struct bnxt *bp)
if (bp->tx_ring) {
for (i = 0; i < bp->tx_nr_rings; i++) {
txr = &bp->tx_ring[i];
- txr->dev_state = BNXT_DEV_STATE_CLOSING;
+ WRITE_ONCE(txr->dev_state, BNXT_DEV_STATE_CLOSING);
}
}
+ /* Make sure napi polls see @dev_state change */
+ synchronize_net();
/* Drop carrier first to prevent TX timeout */
netif_carrier_off(bp->dev);
/* Stop all TX queues */
@@ -9280,8 +9277,10 @@ void bnxt_tx_enable(struct bnxt *bp)
for (i = 0; i < bp->tx_nr_rings; i++) {
txr = &bp->tx_ring[i];
- txr->dev_state = 0;
+ WRITE_ONCE(txr->dev_state, 0);
}
+ /* Make sure napi polls see @dev_state change */
+ synchronize_net();
netif_tx_wake_all_queues(bp->dev);
if (bp->link_info.link_up)
netif_carrier_on(bp->dev);
We can't take the tx lock from the napi poll routine, because netpoll can poll napi at any moment, including with the tx lock already held. It seems that the tx lock is only protecting against the disable path, appropriate barriers are already in place to make sure cleanup can safely run concurrently with start_xmit. I don't see any other reason why 'stopped && avail > thresh' needs to be re-checked under the lock. Remove the tx lock and use synchronize_net() to make sure closing the device does not race we restarting the queues. Annotate accesses to dev_state against data races. Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.") Signed-off-by: Jakub Kicinski <kuba@kernel.org> -- v2: keep the unlikely in bnxt_tx_int() [Edwin] --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)