summaryrefslogtreecommitdiffstats
path: root/kernel/Documentation/networking/timestamping.txt
diff options
context:
space:
mode:
authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/Documentation/networking/timestamping.txt
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/Documentation/networking/timestamping.txt')
-rw-r--r--kernel/Documentation/networking/timestamping.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/Documentation/networking/timestamping.txt b/kernel/Documentation/networking/timestamping.txt
index 5f0922613..a977339fb 100644
--- a/kernel/Documentation/networking/timestamping.txt
+++ b/kernel/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