From 142c0ac445792c492579cb01f1cfd4e32e6dfcce Mon Sep 17 00:00:00 2001 From: Thomas Falcon Date: Sun, 5 Mar 2017 12:18:41 -0600 Subject: [PATCH] ibmvnic: Fix overflowing firmware/hardware TX queue Use a counter to track the number of outstanding transmissions sent that have not received completions. If the counter reaches the maximum number of queue entries, stop transmissions on that queue. As we receive more completions from firmware, wake the queue once the counter reaches an acceptable level. This patch prevents hardware/firmware TX queue from filling up and and generating errors. Since incorporating this fix, internal testing has reported that these firmware errors have stopped. Signed-off-by: Thomas Falcon Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 27 ++++++++++++++++++++++++++- drivers/net/ethernet/ibm/ibmvnic.h | 1 + 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 9198e6b..0e87b83 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -705,6 +705,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) u8 *hdrs = (u8 *)&adapter->tx_rx_desc_req; struct device *dev = &adapter->vdev->dev; struct ibmvnic_tx_buff *tx_buff = NULL; + struct ibmvnic_sub_crq_queue *tx_scrq; struct ibmvnic_tx_pool *tx_pool; unsigned int tx_send_failed = 0; unsigned int tx_map_failed = 0; @@ -724,6 +725,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) int ret = 0; tx_pool = &adapter->tx_pool[queue_num]; + tx_scrq = adapter->tx_scrq[queue_num]; txq = netdev_get_tx_queue(netdev, skb_get_queue_mapping(skb)); handle_array = (u64 *)((u8 *)(adapter->login_rsp_buf) + be32_to_cpu(adapter->login_rsp_buf-> @@ -826,6 +828,14 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) ret = NETDEV_TX_BUSY; goto out; } + + atomic_inc(&tx_scrq->used); + + if (atomic_read(&tx_scrq->used) >= adapter->req_tx_entries_per_subcrq) { + netdev_info(netdev, "Stopping queue %d\n", queue_num); + netif_stop_subqueue(netdev, queue_num); + } + tx_packets++; tx_bytes += skb->len; txq->trans_start = jiffies; @@ -1213,6 +1223,7 @@ static struct ibmvnic_sub_crq_queue *init_sub_crq_queue(struct ibmvnic_adapter scrq->adapter = adapter; scrq->size = 4 * PAGE_SIZE / sizeof(*scrq->msgs); scrq->cur = 0; + atomic_set(&scrq->used, 0); scrq->rx_skb_top = NULL; spin_lock_init(&scrq->lock); @@ -1355,8 +1366,22 @@ restart_loop: DMA_TO_DEVICE); } - if (txbuff->last_frag) + if (txbuff->last_frag) { + atomic_dec(&scrq->used); + + if (atomic_read(&scrq->used) <= + (adapter->req_tx_entries_per_subcrq / 2) && + netif_subqueue_stopped(adapter->netdev, + txbuff->skb)) { + netif_wake_subqueue(adapter->netdev, + scrq->pool_index); + netdev_dbg(adapter->netdev, + "Started queue %d\n", + scrq->pool_index); + } + dev_kfree_skb_any(txbuff->skb); + } adapter->tx_pool[pool].free_map[adapter->tx_pool[pool]. producer_index] = index; diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h index 422824f..1993b42 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.h +++ b/drivers/net/ethernet/ibm/ibmvnic.h @@ -863,6 +863,7 @@ struct ibmvnic_sub_crq_queue { spinlock_t lock; struct sk_buff *rx_skb_top; struct ibmvnic_adapter *adapter; + atomic_t used; }; struct ibmvnic_long_term_buff { -- 2.7.4