Commit Graph

7 Commits

Author SHA1 Message Date
Jakub Kicinski 59cb89e6b7 doc: update driver TX algorithm in timestamping.txt
Since cd4d8fdad1 ("net: kernel panic in dev_hard_start_xmit:
remove faulty software TX time stamping") dev_hard_start_xmit()
will not provide software timestamps. It's a responsibility of
the drivers to call skb_tx_timestamp() at the right time.

Cc: linux-doc@vger.kernel.org
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-18 15:16:48 -04:00
Andrew Lutomirski adca476782 net: Improve SO_TIMESTAMPING documentation and fix a minor code bug
The original documentation was very unclear.

The code fix is presumably related to the formerly unclear
documentation: SOCK_TIMESTAMPING_RX_SOFTWARE has no effect on
__sock_recv_timestamp's behavior, so calling __sock_recv_ts_and_drops
from sock_recv_ts_and_drops if only SOCK_TIMESTAMPING_RX_SOFTWARE is
set is pointless.  This should have no user-observable effect.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06 16:18:01 -05:00
Ben Hutchings fd468c74bd net_tstamp: Add SIOCGHWTSTAMP ioctl to match SIOCSHWTSTAMP
SIOCSHWTSTAMP returns the real configuration to the application
using it, but there is currently no way for any other
application to find out the configuration non-destructively.
Add a new ioctl for this, making it unprivileged.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-11-19 19:07:21 +00:00
Oliver Hartkopp 2244d07bfa net: simplify flags for tx timestamping
This patch removes the abstraction introduced by the union skb_shared_tx in
the shared skb data.

The access of the different union elements at several places led to some
confusion about accessing the shared tx_flags e.g. in skb_orphan_try().

    http://marc.info/?l=linux-netdev&m=128084897415886&w=2

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-19 00:08:30 -07:00
Patrick Loschmidt 69298698c2 net: corrected documentation for hardware time stamping
The current documentation for hardware time stamping does not
correctly specify the available kernel functions since the
implementation was changed later on.

Signed-off-by: Patrick Loschmidt <Patrick.Loschmidt@oeaw.ac.at>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-07 21:52:07 -07:00
Patrick Ohly 51f31cabe3 ip: support for TX timestamps on UDP and RAW sockets
Instructions for time stamping outgoing packets are take from the
socket layer and later copied into the new skb.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-15 22:43:38 -08:00
Patrick Ohly cb9eff0978 net: new user space API for time stamping of incoming and outgoing packets
User space can request hardware and/or software time stamping.
Reporting of the result(s) via a new control message is enabled
separately for each field in the message because some of the
fields may require additional computation and thus cause overhead.
User space can tell the different kinds of time stamps apart
and choose what suits its needs.

When a TX timestamp operation is requested, the TX skb will be cloned
and the clone will be time stamped (in hardware or software) and added
to the socket error queue of the skb, if the skb has a socket
associated with it.

The actual TX timestamp will reach userspace as a RX timestamp on the
cloned packet. If timestamping is requested and no timestamping is
done in the device driver (potentially this may use hardware
timestamping), it will be done in software after the device's
start_hard_xmit routine.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-15 22:43:33 -08:00