From 9ed4cb073438e2154778f0d693d966359afd6549 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 16 Oct 2012 23:56:14 +1030 Subject: virtio_net: don't rely on virtqueue_add_buf() returning capacity. Now we can easily use vq->num_free to determine if there are descriptors left in the queue, we're about to change virtqueue_add_buf() to return 0 on success. The virtio_net driver is the only one which actually uses the return value, so change that. Signed-off-by: Rusty Russell Acked-by: Michael S. Tsirkin --- drivers/net/virtio_net.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6c094c88424e..7c7f5a94ca4f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -471,10 +471,11 @@ static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) err = add_recvbuf_small(vi, gfp); oom = err == -ENOMEM; - if (err < 0) + if (err) break; ++vi->num; - } while (err > 0); + } while (vi->rvq->num_free); + if (unlikely(vi->num > vi->max)) vi->max = vi->num; virtqueue_kick(vi->rvq); @@ -625,27 +626,20 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); - int capacity; + int err; /* Free up any pending old buffers before queueing new ones. */ free_old_xmit_skbs(vi); /* Try to transmit */ - capacity = xmit_skb(vi, skb); + err = xmit_skb(vi, skb); - /* This can happen with OOM and indirect buffers. */ - if (unlikely(capacity < 0)) { - if (likely(capacity == -ENOMEM)) { - if (net_ratelimit()) - dev_warn(&dev->dev, - "TX queue failure: out of memory\n"); - } else { - dev->stats.tx_fifo_errors++; - if (net_ratelimit()) - dev_warn(&dev->dev, - "Unexpected TX queue failure: %d\n", - capacity); - } + /* This should not happen! */ + if (unlikely(err < 0)) { + dev->stats.tx_fifo_errors++; + if (net_ratelimit()) + dev_warn(&dev->dev, + "Unexpected TX queue failure: %d\n", err); dev->stats.tx_dropped++; kfree_skb(skb); return NETDEV_TX_OK; @@ -658,13 +652,12 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) /* Apparently nice girls don't return TX_BUSY; stop the queue * before it gets out of hand. Naturally, this wastes entries. */ - if (capacity < 2+MAX_SKB_FRAGS) { + if (vi->svq->num_free < 2+MAX_SKB_FRAGS) { netif_stop_queue(dev); if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) { /* More just got used, free them then recheck. */ free_old_xmit_skbs(vi); - capacity = vi->svq->num_free; - if (capacity >= 2+MAX_SKB_FRAGS) { + if (vi->svq->num_free >= 2+MAX_SKB_FRAGS) { netif_start_queue(dev); virtqueue_disable_cb(vi->svq); } -- cgit v1.2.3