Re: [PATCH net] net: fec: change the default rx copybreak length to 1518

From: Andrew Lunn
Date: Fri Aug 19 2022 - 12:13:01 EST


On Fri, Aug 19, 2022 at 05:00:41PM +0800, wei.fang@xxxxxxx wrote:
> From: Wei Fang <wei.fang@xxxxxxx>
>
> Set the default rx copybreak value to 1518 so that improve the
> performance when SMMU is enabled. User can change the copybreak
> length in dynamically by ethtool.

Please provide some benchmark for this. And include a range of SoCs
which include the FEC. Maybe this helps for the platform you are
testing on, but is bad for imx25, Vybrid etc?

> + * The driver support .set_tunable() interface for ethtool, user
> + * can dynamicly change the copybreak value.
> + */

Which also means you could change it for your platform. So a patch
like this needs justifying.

Andrew