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-rw-r--r--Documentation/networking/timestamping.rst16
1 files changed, 11 insertions, 5 deletions
diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst
index 61ef9da10e28..7aabead90648 100644
--- a/Documentation/networking/timestamping.rst
+++ b/Documentation/networking/timestamping.rst
@@ -140,6 +140,14 @@ SOF_TIMESTAMPING_TX_ACK:
cumulative acknowledgment. The mechanism ignores SACK and FACK.
This flag can be enabled via both socket options and control messages.
+SOF_TIMESTAMPING_TX_COMPLETION:
+ Request tx timestamps on packet tx completion. The completion
+ timestamp is generated by the kernel when it receives packet a
+ completion report from the hardware. Hardware may report multiple
+ packets at once, and completion timestamps reflect the timing of the
+ report and not actual tx time. This flag can be enabled via both
+ socket options and control messages.
+
1.3.2 Timestamp Reporting
^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -803,11 +811,9 @@ Documentation/devicetree/bindings/ptp/timestamper.txt for more details.
3.2.4 Other caveats for MAC drivers
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Stacked PHCs, especially DSA (but not only) - since that doesn't require any
-modification to MAC drivers, so it is more difficult to ensure correctness of
-all possible code paths - is that they uncover bugs which were impossible to
-trigger before the existence of stacked PTP clocks. One example has to do with
-this line of code, already presented earlier::
+The use of stacked PHCs may uncover MAC driver bugs which were impossible to
+trigger without them. One example has to do with this line of code, already
+presented earlier::
skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;