net: fec: add support for dumping transmit ring on timeout
When we timeout on transmit, it would be useful to dump the transmit
ring, so we can see the ring state. This can be helpful to diagnose
the cause of transmit timeouts.
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index c6b1bf7..09fcdc7 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -320,6 +320,27 @@
return bufaddr;
}
+static void fec_dump(struct net_device *ndev)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ struct bufdesc *bdp = fep->tx_bd_base;
+ unsigned int index = 0;
+
+ netdev_info(ndev, "TX ring dump\n");
+ pr_info("Nr SC addr len SKB\n");
+
+ do {
+ pr_info("%3u %c%c 0x%04x 0x%08lx %4u %p\n",
+ index,
+ bdp == fep->cur_tx ? 'S' : ' ',
+ bdp == fep->dirty_tx ? 'H' : ' ',
+ bdp->cbd_sc, bdp->cbd_bufaddr, bdp->cbd_datlen,
+ fep->tx_skbuff[index]);
+ bdp = fec_enet_get_nextdesc(bdp, fep);
+ index++;
+ } while (bdp != fep->tx_bd_base);
+}
+
static inline bool is_ipv4_pkt(struct sk_buff *skb)
{
return skb->protocol == htons(ETH_P_IP) && ip_hdr(skb)->version == 4;
@@ -1018,6 +1039,8 @@
{
struct fec_enet_private *fep = netdev_priv(ndev);
+ fec_dump(ndev);
+
ndev->stats.tx_errors++;
schedule_work(&fep->tx_timeout_work);