[PATCH net-next v2] net: stmmac: Caclucate CDC error only once

[Matteo Croce]

On Mon, Nov 22, 2021 at 12:19 PM Kurt Kanzenbach <kurt at linutronix.de> wrote:
>
> The clock domain crossing error (CDC) is calculated at every fetch of Tx or Rx
> timestamps. It includes a division. Especially on arm32 based systems it is
> expensive. It also requires two conditionals in the hotpath.
>
> Add a compensation value cache to struct plat_stmmacenet_data and subtract it
> unconditionally in the RX/TX functions which spares the conditionals.
>
> The value is initialized to 0 and if supported calculated in the PTP
> initialization code.
>
> Suggested-by: Thomas Gleixner <tglx at linutronix.de>
> Signed-off-by: Kurt Kanzenbach <kurt at linutronix.de>
> ---

Nit: "Caclucate" in the subject

-- 
per aspera ad upstream