diff options
| -rw-r--r-- | Documentation/networking/timestamping.txt | 10 | ||||
| -rw-r--r-- | include/linux/skbuff.h | 6 |
2 files changed, 12 insertions, 4 deletions
diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index bc3554124903..8b4ad809df27 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -40,7 +40,7 @@ the set bits correspond to data that is available, then the control message will not be generated: SOF_TIMESTAMPING_SOFTWARE: report systime if available -SOF_TIMESTAMPING_SYS_HARDWARE: report hwtimetrans if available +SOF_TIMESTAMPING_SYS_HARDWARE: report hwtimetrans if available (deprecated) SOF_TIMESTAMPING_RAW_HARDWARE: report hwtimeraw if available It is worth noting that timestamps may be collected for reasons other @@ -94,7 +94,13 @@ not perfect; as a consequence, sorting packets received via different NICs by their hwtimetrans may differ from the order in which they were received. hwtimetrans may be non-monotonic even for the same NIC. Filled in if SOF_TIMESTAMPING_SYS_HARDWARE is set. Requires support -by the network device and will be empty without that support. +by the network device and will be empty without that support. This +field is DEPRECATED. Only one driver computes this value. New device +drivers must leave this zero. Instead, they can expose the hardware +clock device on the NIC directly as a HW PTP clock source, to allow +time conversion in userspace and optionally synchronize system time +with a userspace PTP stack such as linuxptp. For the PTP clock API, +see Documentation/ptp/ptp.txt. SIOCSHWTSTAMP, SIOCGHWTSTAMP: diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 890fb3307dd6..369430340ed9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -211,7 +211,7 @@ static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) * struct skb_shared_hwtstamps - hardware time stamps * @hwtstamp: hardware time stamp transformed into duration * since arbitrary point in time - * @syststamp: hwtstamp transformed to system time base + * @syststamp: hwtstamp transformed to system time base (deprecated) * * Software time stamps generated by ktime_get_real() are stored in * skb->tstamp. The relation between the different kinds of time @@ -222,7 +222,9 @@ static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) * syststamp/tstamp/"syststamp from other device" comparison is * limited by the accuracy of the transformation into system time * base. This depends on the device driver and its underlying - * hardware. + * hardware. The syststamp implementation is deprecated in favor + * of hwtstamps and hw PTP clock sources exposed directly to + * userspace. * * hwtstamps can only be compared against other hwtstamps from * the same device. |