From b4727e69b81b71c6e9696185091e8256d863f9be Mon Sep 17 00:00:00 2001 From: Sebastian Siewior Date: Tue, 23 Apr 2013 07:31:39 +0000 Subject: [PATCH] net/cpsw: redo rx skb allocation in rx path In case that we run into OOM during the allocation of the new rx-skb we don't get one and we have one skb less than we used to have. If this continues to happen then we end up with no rx-skbs at all. This patch changes the following: - if we fail to allocate the new skb, then we treat the currently completed skb as the new one and so drop the currently received data. - instead of testing multiple times if the device is gone we rely one the status field which is set to -ENOSYS in case the channel is going down and incomplete requests are purged. cpdma_chan_stop() removes most of the packages with -ENOSYS. The currently active packet which is removed has the "tear down" bit set. So if that bit is set, we send ENOSYS as well otherwise we pass the status bits which are required to figure out which of the two possible just finished. Acked-by: Mugunthan V N Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: David S. Miller --- drivers/net/ethernet/ti/cpsw.c | 33 ++++++++++--------------- drivers/net/ethernet/ti/davinci_cpdma.c | 7 +++++- 2 files changed, 19 insertions(+), 21 deletions(-) diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c index 05f11b854d0a..a066c41beac7 100644 --- a/drivers/net/ethernet/ti/cpsw.c +++ b/drivers/net/ethernet/ti/cpsw.c @@ -468,43 +468,36 @@ void cpsw_tx_handler(void *token, int len, int status) void cpsw_rx_handler(void *token, int len, int status) { struct sk_buff *skb = token; + struct sk_buff *new_skb; struct net_device *ndev = skb->dev; struct cpsw_priv *priv = netdev_priv(ndev); int ret = 0; cpsw_dual_emac_src_port_detect(status, priv, ndev, skb); - /* free and bail if we are shutting down */ - if (unlikely(!netif_running(ndev)) || - unlikely(!netif_carrier_ok(ndev))) { + if (unlikely(status < 0)) { + /* the interface is going down, skbs are purged */ dev_kfree_skb_any(skb); return; } - if (likely(status >= 0)) { + + new_skb = netdev_alloc_skb_ip_align(ndev, priv->rx_packet_max); + if (new_skb) { skb_put(skb, len); cpts_rx_timestamp(priv->cpts, skb); skb->protocol = eth_type_trans(skb, ndev); netif_receive_skb(skb); priv->stats.rx_bytes += len; priv->stats.rx_packets++; - skb = NULL; - } - - if (unlikely(!netif_running(ndev))) { - if (skb) - dev_kfree_skb_any(skb); - return; + } else { + priv->stats.rx_dropped++; + new_skb = skb; } - if (likely(!skb)) { - skb = netdev_alloc_skb_ip_align(ndev, priv->rx_packet_max); - if (WARN_ON(!skb)) - return; - - ret = cpdma_chan_submit(priv->rxch, skb, skb->data, - skb_tailroom(skb), 0); - } - WARN_ON(ret < 0); + ret = cpdma_chan_submit(priv->rxch, new_skb, new_skb->data, + skb_tailroom(new_skb), 0); + if (WARN_ON(ret < 0)) + dev_kfree_skb_any(new_skb); } static irqreturn_t cpsw_interrupt(int irq, void *dev_id) diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c index 3cc20e7da01b..6b0a89f6f6a5 100644 --- a/drivers/net/ethernet/ti/davinci_cpdma.c +++ b/drivers/net/ethernet/ti/davinci_cpdma.c @@ -776,6 +776,7 @@ static int __cpdma_chan_process(struct cpdma_chan *chan) struct cpdma_ctlr *ctlr = chan->ctlr; struct cpdma_desc __iomem *desc; int status, outlen; + int cb_status = 0; struct cpdma_desc_pool *pool = ctlr->pool; dma_addr_t desc_dma; unsigned long flags; @@ -811,8 +812,12 @@ static int __cpdma_chan_process(struct cpdma_chan *chan) } spin_unlock_irqrestore(&chan->lock, flags); + if (unlikely(status & CPDMA_DESC_TD_COMPLETE)) + cb_status = -ENOSYS; + else + cb_status = status; - __cpdma_chan_free(chan, desc, outlen, status); + __cpdma_chan_free(chan, desc, outlen, cb_status); return status; unlock_ret: -- 2.20.1