From: Jakub Kicinski <kuba@kernel.org>
To: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
John Fraker <jfraker@google.com>,
netdev@vger.kernel.org,
Praveen Kaligineedi <pkaligineedi@google.com>,
Harshitha Ramamurthy <hramamurthy@google.com>,
Shailend Chand <shailend@google.com>,
Willem de Bruijn <willemb@google.com>,
"David S. Miller" <davem@davemloft.net>,
Junfeng Guo <junfeng.guo@intel.com>,
Ziwei Xiao <ziweixiao@google.com>,
Jeroen de Borst <jeroendb@google.com>,
linux-kernel@vger.kernel.org, kory.maincent@bootlin.com,
andrew@lunn.ch, richardcochran@gmail.com
Subject: Re: [PATCH net-next] gve: Correctly report software timestamping capabilities
Date: Wed, 10 Apr 2024 06:19:28 -0700 [thread overview]
Message-ID: <20240410061928.712ff9a3@kernel.org> (raw)
In-Reply-To: <87jzl5akh5.fsf@nvidia.com>
On Tue, 09 Apr 2024 21:40:46 -0700 Rahul Rameshbabu wrote:
> > My gut tells me we force drivers to set the ethtool op because
> > while at it they will probably also implement tx stamping.
>
> I think the logic should be the other way (in terms of the
> relationship). A call to skb_tx_timestamp should throw a warning if the
> driver does not advertise its timestamping capabilities. This way, a
> naive netdev driver for some lightweight device does not need to worry
> about this. I agree that anyone implementing tx timestamping should have
> this operation defined. An skb does not contain any mechanism to
> reference the driver's ethtool callback. Maybe the right choice is to
> have a ts capability function registered for each netdev that can be
> used by the core stack and that powers the ethtool operation as well
> instead of the existing callback for ethtool?
Adding a check which only need to runs once in the lifetime of
the driver to the fastpath may be a little awkward. Another option
would be a sufficiently intelligent grep, which would understand
which files constitute a driver. At which point grepping for
the ethtool op and skb_tx_timestamp would be trivial?
next prev parent reply other threads:[~2024-04-10 13:19 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-08 18:09 [PATCH net-next] gve: Correctly report software timestamping capabilities John Fraker
2024-04-09 14:29 ` Willem de Bruijn
2024-04-10 0:28 ` Jakub Kicinski
2024-04-10 4:40 ` Rahul Rameshbabu
2024-04-10 13:19 ` Jakub Kicinski [this message]
2024-04-10 19:31 ` Willem de Bruijn
2024-04-11 0:40 ` Rahul Rameshbabu
2024-04-11 1:36 ` Willem de Bruijn
2024-04-10 0:26 ` Jakub Kicinski
2024-04-11 3:22 ` Willem de Bruijn
2024-04-11 19:37 ` John Fraker
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