Re: [PATCH v2 net 3/6] net: enetc: take the MDIO lock only once per NAPI poll cycle

[Andrew Lunn]

On Thu, Feb 25, 2021 at 02:18:32PM +0200, Vladimir Oltean wrote:
> @@ -327,8 +329,8 @@ static void enetc_get_tx_tstamp(struct enetc_hw *hw, 
> union enetc_tx_bd *txbd,
>  {
>       u32 lo, hi, tstamp_lo;
>  
> -     lo = enetc_rd(hw, ENETC_SICTR0);
> -     hi = enetc_rd(hw, ENETC_SICTR1);
> +     lo = enetc_rd_hot(hw, ENETC_SICTR0);
> +     hi = enetc_rd_hot(hw, ENETC_SICTR1);
>       tstamp_lo = le32_to_cpu(txbd->wb.tstamp);
>       if (lo <= tstamp_lo)
>               hi -= 1;

Hi Vladimir

This change is not obvious, and there is no mention of it in the
commit message. Please could you explain it. I guess it is to do with
enetc_get_tx_tstamp() being called with the MDIO lock held now, when
it was not before?

Thanks
        Andrew