From: Tom Barbette <barbette@kth.se>
To: "dev@dpdk.org" <dev@dpdk.org>
Cc: "shahafs@mellanox.com" <shahafs@mellanox.com>,
"yskoh@mellanox.com" <yskoh@mellanox.com>,
"john.mcnamara@intel.com" <john.mcnamara@intel.com>,
"marko.kovacevic@intel.com" <marko.kovacevic@intel.com>
Subject: [dpdk-dev] MLX5 should define the timestamp field in the doc
Date: Tue, 4 Sep 2018 14:26:02 +0000 [thread overview]
Message-ID: <1536071162684.44442@kth.se> (raw)
Hi all,
As far as I know, MLX5 is the only driver to support hardware timestamping.
It would be great to update the doc to explain what the hardware timestamp is supposed to be. If it's nanoseconds, then just a shift regarding system time is enough ? Does it also need a multiplication? Can we query that from hardware? Or provide a piece of code to be used. As it, the feature is useless...
It would be interesting to normalize the hardware timestamping. I guess for any driver, an offset and a multiplication(shift+multiplier eventually) would be enough, and the API should be updated to provide a function to convert a hardware timestamp to software (or that should be part of the driver and done automatically if offloading is enabled?) and probably one to initialize the time, much like the Linux one at https://elixir.bootlin.com/linux/v4.18.5/source/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c#L488 .
Thanks,
Tom
?
next reply other threads:[~2018-09-04 14:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-04 14:26 Tom Barbette [this message]
2018-09-05 5:29 ` Shahaf Shuler
2018-09-05 7:11 ` Tom Barbette
2018-09-05 8:18 ` Shahaf Shuler
2018-09-05 9:00 ` Tom Barbette
2018-09-06 9:07 ` Shahaf Shuler
2018-09-06 9:33 ` Tom Barbette
2018-09-06 14:21 ` Shahaf Shuler
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