# Re: \[PATCH V4 net-next 4/6\] ethtool: extend ringparam setting uAPI with rx\_buf\_len

- From: Marc Kleine-Budde \<mkl@pengutronix.de\>
- Date: 2021-10-25 13:28:13 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/10/11214423
- Thread: https://ratatoskr.run/netdev/2021/10/11213412/t.md

```text
On 25.10.2021 15:11:49, Marc Kleine-Budde wrote:
> On 14.10.2021 19:39:41, Guangbin Huang wrote:
> > From: Hao Chen <redacted>
> > 
> > Add two new parameters ringparam_ext and extack for
> > .get_ringparam and .set_ringparam to extend more ring params
> > through netlink.
> > 
> > Signed-off-by: Hao Chen <redacted>
> > Signed-off-by: Guangbin Huang <redacted>
> 
> While discussing a different ethtool ring param extension,

Let me explain my requirements:

There is a not Ethernet based bus system, called CAN (mainly used in the
automotive and industrial world). It comes in 2 different generations or
modes (CAN-2.0 and CAN-FD) and the 3rd one CAN-XL has already been
specified.

Due to different frame sizes used in these CAN modes and HW limitations,
we need the possibility to set a RX/TX ring configuration for each of
these modes.

The approach Andrew suggested is two-fold. First introduce a "struct
ethtool_kringparam" that's only used inside the kernel, as "struct
ethtool_ringparam" is ABI. Then extend "struct ethtool_kringparam" as
needed.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |
```

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