diff options
| author | Vladimir Oltean <olteanv@gmail.com> | 2021-03-10 16:50:44 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-03-10 12:45:16 -0800 |
| commit | 847cbfc014adafeac401e19e349b0fd524f201c3 (patch) | |
| tree | 54bd8b80cdc06c39573fd793dc54054163d3d683 /include/net/pkt_sched.h | |
| parent | aa27b8f7a048f1cf888b1cb67160e26e069a263c (diff) | |
net: add a helper to avoid issues with HW TX timestamping and SO_TXTIME
As explained in commit 29d98f54a4fe ("net: enetc: allow hardware
timestamping on TX queues with tc-etf enabled"), hardware TX
timestamping requires an skb with skb->tstamp = 0. When a packet is sent
with SO_TXTIME, the skb->skb_mstamp_ns corrupts the value of skb->tstamp,
so the drivers need to explicitly reset skb->tstamp to zero after
consuming the TX time.
Create a helper named skb_txtime_consumed() which does just that. All
drivers which offload TC_SETUP_QDISC_ETF should implement it, and it
would make it easier to assess during review whether they do the right
thing in order to be compatible with hardware timestamping or not.
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/pkt_sched.h')
| -rw-r--r-- | include/net/pkt_sched.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h index 15b1b30f454e..f5c1bee0cd6a 100644 --- a/include/net/pkt_sched.h +++ b/include/net/pkt_sched.h @@ -188,4 +188,13 @@ struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload *offload); void taprio_offload_free(struct tc_taprio_qopt_offload *offload); +/* Ensure skb_mstamp_ns, which might have been populated with the txtime, is + * not mistaken for a software timestamp, because this will otherwise prevent + * the dispatch of hardware timestamps to the socket. + */ +static inline void skb_txtime_consumed(struct sk_buff *skb) +{ + skb->tstamp = ktime_set(0, 0); +} + #endif |