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authorVladimir Oltean <vladimir.oltean@nxp.com>2020-09-18 04:07:23 +0300
committerDavid S. Miller <davem@davemloft.net>2020-09-18 13:52:33 -0700
commit9dda66acddcbcd5c9e94a1292c679738ba999345 (patch)
tree322ee6047f34ea67788d265697215403cc397156 /drivers/net/ethernet/mscc
parent5f6857e808a8bd078296575b417c4b9d160b9779 (diff)
net: mscc: ocelot: fix race condition with TX timestamping
The TX-timestampable skb is added late to the ocelot_port->tx_skbs. It is in a race with the TX timestamp IRQ, which checks that queue trying to match the timestamp with the skb by the ts_id. The skb should be added to the queue before the IRQ can fire. Fixes: 4e3b0468e6d7 ("net: mscc: PTP Hardware Clock (PHC) support") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mscc')
-rw-r--r--drivers/net/ethernet/mscc/ocelot_net.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 0668d23cdbfa..cacabc23215a 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -330,6 +330,7 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
u8 grp = 0; /* Send everything on CPU group 0 */
unsigned int i, count, last;
int port = priv->chip_port;
+ bool do_tstamp;
val = ocelot_read(ocelot, QS_INJ_STATUS);
if (!(val & QS_INJ_STATUS_FIFO_RDY(BIT(grp))) ||
@@ -344,10 +345,14 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
info.vid = skb_vlan_tag_get(skb);
/* Check if timestamping is needed */
+ do_tstamp = (ocelot_port_add_txtstamp_skb(ocelot_port, skb) == 0);
+
if (ocelot->ptp && shinfo->tx_flags & SKBTX_HW_TSTAMP) {
info.rew_op = ocelot_port->ptp_cmd;
- if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)
+ if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
info.rew_op |= (ocelot_port->ts_id % 4) << 3;
+ ocelot_port->ts_id++;
+ }
}
ocelot_gen_ifh(ifh, &info);
@@ -380,12 +385,9 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
- if (!ocelot_port_add_txtstamp_skb(ocelot_port, skb)) {
- ocelot_port->ts_id++;
- return NETDEV_TX_OK;
- }
+ if (!do_tstamp)
+ dev_kfree_skb_any(skb);
- dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}