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 <mugunthanvnm@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 05f11b8..a066c41 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -468,43 +468,36 @@
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;
+ } else {
+ priv->stats.rx_dropped++;
+ new_skb = skb;
}
- if (unlikely(!netif_running(ndev))) {
- if (skb)
- dev_kfree_skb_any(skb);
- return;
- }
-
- 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)