From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 15 Dec 2015 14:52:16 -0300 Subject: Linux-libre 4.3.2-gnu --- Documentation/networking/timestamping.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation/networking/timestamping.txt') diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 5f0922613..a977339fb 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -359,6 +359,13 @@ the requested fine-grained filtering for incoming packets is not supported, the driver may time stamp more than just the requested types of packets. +Drivers are free to use a more permissive configuration than the requested +configuration. It is expected that drivers should only implement directly the +most generic mode that can be supported. For example if the hardware can +support HWTSTAMP_FILTER_V2_EVENT, then it should generally always upscale +HWTSTAMP_FILTER_V2_L2_SYNC_MESSAGE, and so forth, as HWTSTAMP_FILTER_V2_EVENT +is more generic (and more useful to applications). + A driver which supports hardware time stamping shall update the struct with the actual, possibly more permissive configuration. If the requested packets cannot be time stamped, then nothing should be -- cgit v1.2.3-54-g00ecf