net: remove deprecated syststamp timestamp
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>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index b613557..281dece 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -210,20 +210,9 @@
* 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 (deprecated)
*
* Software time stamps generated by ktime_get_real() are stored in
- * skb->tstamp. The relation between the different kinds of time
- * stamps is as follows:
- *
- * syststamp and tstamp can be compared against each other in
- * arbitrary combinations. The accuracy of a
- * 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. The syststamp implementation is deprecated in favor
- * of hwtstamps and hw PTP clock sources exposed directly to
- * userspace.
+ * skb->tstamp.
*
* hwtstamps can only be compared against other hwtstamps from
* the same device.
@@ -233,7 +222,6 @@
*/
struct skb_shared_hwtstamps {
ktime_t hwtstamp;
- ktime_t syststamp;
};
/* Definitions for tx_flags in struct skb_shared_info */