From dc574f1d52d893f516f3786ff7635450bac00eef Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Thu, 28 Mar 2013 11:32:44 +0000 Subject: [PATCH] net: calxedaxgmac: fix rx ring handling when OOM If skb allocation for the rx ring fails repeatedly, we can reach a point were the ring is empty. In this condition, the driver is out of sync with the h/w. While this has always been possible, the removal of the skb recycling seems to have made triggering this problem easier. Signed-off-by: Rob Herring Signed-off-by: David S. Miller --- drivers/net/ethernet/calxeda/xgmac.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c index a170065b5973..bb1e80bfa78a 100644 --- a/drivers/net/ethernet/calxeda/xgmac.c +++ b/drivers/net/ethernet/calxeda/xgmac.c @@ -1141,6 +1141,9 @@ static int xgmac_rx(struct xgmac_priv *priv, int limit) struct sk_buff *skb; int frame_len; + if (!dma_ring_cnt(priv->rx_head, priv->rx_tail, DMA_RX_RING_SZ)) + break; + entry = priv->rx_tail; p = priv->dma_rx + entry; if (desc_get_owner(p)) -- 2.20.1