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2014-09-02net-timestamp: expand documentationWillem de Bruijn1-82/+286
Expand Documentation/networking/timestamping.txt with new interfaces and bytestream timestamping. Also minor cleanup of the other text. Import txtimestamp.c test of the new features. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-29net: remove deprecated syststamp timestampWillem de Bruijn1-10/+2
The SO_TIMESTAMPING API defines three types of timestamps: software, hardware in raw format (hwtstamp) and hardware converted to system format (syststamp). The last has been deprecated in favor of combining hwtstamp with a PTP clock driver. There are no active users in the kernel. The option was device driver dependent. If set, but without hardware support, the correct behavior is to return zero in the relevant field in the SCM_TIMESTAMPING ancillary message. Without device drivers implementing the option, this field is effectively always zero. Remove the internal plumbing to dissuage new drivers from implementing the feature. Keep the SOF_TIMESTAMPING_SYS_HARDWARE flag, however, to avoid breaking existing applications that request the timestamp. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-16net-timestamp: document deprecated syststampWillem de Bruijn1-2/+8
The SO_TIMESTAMPING API defines option SOF_TIMESTAMPING_SYS_HW. This feature is deprecated. It should not be implemented by new device drivers. Existing drivers do not implement it, either -- with one exception. Driver developers are encouraged to expose the NIC hw clock as a PTP HW clock source, instead, and synchronize system time to the HW source. The control flag cannot be removed due to being part of the ABI, nor can the structure scm_timestamping that is returned. Due to the one legacy driver, the internal datapath and structure are not removed. This patch only clearly marks the interface as deprecated. Device drivers should always return a syststamp value of zero. Signed-off-by: Willem de Bruijn <willemb@google.com> ---- We can consider adding a WARN_ON_ONCE in__sock_recv_timestamp if non-zero syststamp is encountered Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-18doc: update driver TX algorithm in timestamping.txtJakub Kicinski1-3/+3
Since cd4d8fdad1f1 ("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>
2014-03-07net: Improve SO_TIMESTAMPING documentation and fix a minor code bugAndrew Lutomirski1-20/+32
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>
2013-11-19net_tstamp: Add SIOCGHWTSTAMP ioctl to match SIOCSHWTSTAMPBen Hutchings1-2/+7
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>
2010-08-19net: simplify flags for tx timestampingOliver Hartkopp1-9/+13
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>
2010-04-08net: corrected documentation for hardware time stampingPatrick Loschmidt1-30/+46
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>
2009-02-16ip: support for TX timestamps on UDP and RAW socketsPatrick Ohly1-0/+2
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>
2009-02-16net: new user space API for time stamping of incoming and outgoing packetsPatrick Ohly1-0/+178
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>