aquantia: Fix Tx queue hangups

Driver did a poor job in managing its Tx queues: Sometimes it could stop
tx queues due to link down condition in aq_nic_xmit - but never waked up
them. That led to Tx path total suspend.
This patch fixes this and improves generic queue management:
- introduces queue restart counter
- uses generic netif_ interface to disable and enable tx path
- refactors link up/down condition and introduces dmesg log event when
  link changes.
- introduces new constant for minimum descriptors count required for queue
  wakeup

Signed-off-by: Pavel Belous <Pavel.Belous@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 6 deletions

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_vec.c b/drivers/net/ethernet/aquantia/atlantic/aq_vec.c
index ebf588004c46..305ff8ffac2c 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_vec.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_vec.c
@@ -59,12 +59,7 @@ static int aq_vec_poll(struct napi_struct *napi, int budget)
 			if (ring[AQ_VEC_TX_ID].sw_head !=
 			    ring[AQ_VEC_TX_ID].hw_head) {
 				aq_ring_tx_clean(&ring[AQ_VEC_TX_ID]);
-
-				if (aq_ring_avail_dx(&ring[AQ_VEC_TX_ID]) >
-				    AQ_CFG_SKB_FRAGS_MAX) {
-					aq_nic_ndev_queue_start(self->aq_nic,
-						ring[AQ_VEC_TX_ID].idx);
-				}
+				aq_ring_update_queue_state(&ring[AQ_VEC_TX_ID]);
 				was_tx_cleaned = true;
 			}
 
@@ -364,6 +359,7 @@ void aq_vec_add_stats(struct aq_vec_s *self,
 		stats_tx->packets += tx->packets;
 		stats_tx->bytes += tx->bytes;
 		stats_tx->errors += tx->errors;
+		stats_tx->queue_restarts += tx->queue_restarts;
 	}
 }