Re: [PATCH net-next v2 2/3] net: stmmac: dwmac-renesas-gbeth: Use OF data for configuration

[Lad, Prabhakar]

Hi Russell,

On Thu, Sep 4, 2025 at 9:49 PM Russell King (Oracle)
<linux@xxxxxxxxxxxxxxx> wrote:
>
> On Thu, Sep 04, 2025 at 09:39:48PM +0100, Prabhakar wrote:
> >       plat_dat->init = renesas_gbeth_init;
> >       plat_dat->exit = renesas_gbeth_exit;
> > -     plat_dat->flags |= STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY |
> > -                        STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP |
> > -                        STMMAC_FLAG_SPH_DISABLE;
> > +     plat_dat->flags |= gbeth->of_data->stmmac_flags;
>
> You include the first two flags in your new device. I would like to see
> at least STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP always being set. The only
> reason we have the STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP flag is to avoid
> changing existing behaviour and causing regressions. New stuff should
> always set this.
>
Me confused, STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP flag is set in the new
device [0]. The reason STMMAC_FLAG_SPH_DISABLE flag being dropped in
the new device is SPHEN=1 in MAC HW feature reg for the new device.

[0] https://lore.kernel.org/all/20250904203949.292066-4-prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx/

Cheers,
Prabhakar

> If there is a reason not to have this set (e.g., PCS doesn't support
> it) then we need to make that a PCS property and extend phylink's EEE
> support. If there's something wrong in the setup that stmmac does for
> EEE, then I'd like to hear about it as well.
>
> Thanks.
>
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