diff options
author | Vedang Patel | 2019-06-26 00:07:12 +0200 |
---|---|---|
committer | David S. Miller | 2019-06-28 23:45:33 +0200 |
commit | 1e08511d5d01884a3c9070afd52a47799312074a (patch) | |
tree | ea2cfeaae03de3b7c71c728d65a550d16de9711c /include/acpi/actbl3.h | |
parent | Merge branch 'mirred-recurse' (diff) | |
download | kernel-qcow2-linux-1e08511d5d01884a3c9070afd52a47799312074a.tar.gz kernel-qcow2-linux-1e08511d5d01884a3c9070afd52a47799312074a.tar.xz kernel-qcow2-linux-1e08511d5d01884a3c9070afd52a47799312074a.zip |
igb: clear out skb->tstamp after reading the txtime
If a packet which is utilizing the launchtime feature (via SO_TXTIME socket
option) also requests the hardware transmit timestamp, the hardware
timestamp is not delivered to the userspace. This is because the value in
skb->tstamp is mistaken as the software timestamp.
Applications, like ptp4l, request a hardware timestamp by setting the
SOF_TIMESTAMPING_TX_HARDWARE socket option. Whenever a new timestamp is
detected by the driver (this work is done in igb_ptp_tx_work() which calls
igb_ptp_tx_hwtstamps() in igb_ptp.c[1]), it will queue the timestamp in the
ERR_QUEUE for the userspace to read. When the userspace is ready, it will
issue a recvmsg() call to collect this timestamp. The problem is in this
recvmsg() call. If the skb->tstamp is not cleared out, it will be
interpreted as a software timestamp and the hardware tx timestamp will not
be successfully sent to the userspace. Look at skb_is_swtx_tstamp() and the
callee function __sock_recv_timestamp() in net/socket.c for more details.
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/acpi/actbl3.h')
0 files changed, 0 insertions, 0 deletions