Re: [PATCH net-next v10 01/11] net: stmmac: move XPCS lifetime management to platform drivers

[netdev-bot+sashiko@kernel.org]

Thank you for your contribution! Sashiko AI review found more severe
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you want to address the nit picks below when you respin.

Low priority / nit picks for your consideration:

- [Low] Commit message audit claim: "every DTS that pairs a dwmac node
  with a PCS goes through a glue that sets pcs_init() (Intel, Renesas,…
- [Low] Commit message framing: the removal of the unconditional
  `priv->hw->xpcs = xpcs;` in stmmac_pcs_setup() is described as fixing…

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net: stmmac: move XPCS lifetime management to platform drivers

This moves XPCS creation and destruction out of the common
stmmac_pcs_setup() and stmmac_pcs_clean(), which now only dispatch to
plat->pcs_init() and plat->pcs_exit(). The Intel mGbE glue gains its own
pcs_init()/pcs_exit() pair, and the renesas-gbeth, rzn1 and socfpga
pcs_exit() callbacks clear priv->hw->phylink_pcs after destroying the PCS.

No Link: tags are present in the commit header.

I looked at the two places in stmmac_pcs_setup() that seemed worth double
checking and did not find anything to report.

> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> index afe98ff5bdcb0..7396b68899c66 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> @@ -426,35 +426,14 @@ int stmmac_mdio_reset(struct mii_bus *bus)
>  int stmmac_pcs_setup(struct net_device *ndev)
>  {
>  	struct stmmac_priv *priv = netdev_priv(ndev);
> -	struct fwnode_handle *devnode, *pcsnode;
> -	struct dw_xpcs *xpcs = NULL;
> -	int addr, ret;
> -
> -	devnode = dev_fwnode(priv->device);
> -
> -	if (priv->plat->pcs_init) {
> -		ret = priv->plat->pcs_init(priv);
> -	} else if (fwnode_property_present(devnode, "pcs-handle")) {
> -		pcsnode = fwnode_find_reference(devnode, "pcs-handle", 0);
> -		xpcs = xpcs_create_fwnode(pcsnode);
> -		fwnode_handle_put(pcsnode);
> -		ret = PTR_ERR_OR_ZERO(xpcs);
> -	} else if (priv->plat->mdio_bus_data &&
> -		   priv->plat->mdio_bus_data->pcs_mask) {
> -		addr = ffs(priv->plat->mdio_bus_data->pcs_mask) - 1;
> -		xpcs = xpcs_create_mdiodev(priv->mii, addr);
> -		ret = PTR_ERR_OR_ZERO(xpcs);
> -	} else {
> +	int ret;
> +
> +	if (!priv->plat->pcs_init)
>  		return 0;
> -	}

Dropping the generic "pcs-handle" and pcs_mask parsing here matches the
in-tree users I could find: the only dwmac nodes carrying pcs-handle go
through dwmac-rzn1 (r9a06g032.dtsi) and dwmac-renesas-gbeth, both of which
set plat->pcs_init(), and dwmac-intel gains pcs_init() in this same patch.

>  
> +	ret = priv->plat->pcs_init(priv);
>  	if (ret)
> -		return dev_err_probe(priv->device, ret, "No xPCS found\n");
> -
> -	if (xpcs)
> -		xpcs_config_eee_mult_fact(xpcs, priv->plat->mult_fact_100ns);
> -
> -	priv->hw->xpcs = xpcs;
> +		return dev_err_probe(priv->device, ret, "Failed to initialize PCS\n");
>  
>  	return 0;
>  }

Removing the trailing priv->hw->xpcs assignment also looks right. None of
the pcs_init() implementations present before this patch touch
priv->hw->xpcs (renesas_gmac_pcs_init(), rzn1_dwmac_pcs_init() and
socfpga_dwmac_pcs_init() all set priv->hw->phylink_pcs), so no existing
platform changes behaviour, and a glue that does set priv->hw->xpcs from
pcs_init() would previously have had it clobbered.

> @@ -463,14 +442,10 @@ void stmmac_pcs_clean(struct net_device *ndev)
>  {
>  	struct stmmac_priv *priv = netdev_priv(ndev);
>  
> -	if (priv->plat->pcs_exit)
> -		priv->plat->pcs_exit(priv);
> -
> -	if (!priv->hw->xpcs)
> +	if (!priv->plat->pcs_exit)
>  		return;
>  
> -	xpcs_destroy(priv->hw->xpcs);
> -	priv->hw->xpcs = NULL;
> +	priv->plat->pcs_exit(priv);
>  }

The Intel side pairs this with intel_mgbe_pcs_exit(), which calls
xpcs_destroy() and clears priv->hw->xpcs, so the destroy path is preserved
for the only platform that was relying on the common code.

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Sashiko AI review · https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260922200336.2201212-1-coiaprant%40gmail.com