Re: [PATCH net-next v3 2/5] net: stmmac: introduce pcs_init/pcs_exit stmmac operations

From: Serge Semin
Date: Tue Apr 16 2024 - 09:41:54 EST


Hi Romain, Russell

On Mon, Apr 15, 2024 at 11:18:42AM +0200, Romain Gantois wrote:
> From: "Russell King (Oracle)" <rmk+kernel@xxxxxxxxxxxxxxx>
>
> Introduce a mechanism whereby platforms can create their PCS instances
> prior to the network device being published to userspace, but after
> some of the core stmmac initialisation has been completed. This means
> that the data structures that platforms need will be available.
>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
> Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
> Signed-off-by: Romain Gantois <romain.gantois@xxxxxxxxxxx>
> ---
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 14 ++++++++++++++
> include/linux/stmmac.h | 2 ++
> 2 files changed, 16 insertions(+)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index fe3498e86de9d..25fa33ae7017b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -7208,6 +7208,12 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
> if (ret)
> return ret;
>
> + if (priv->plat->pcs_init) {
> + ret = priv->plat->pcs_init(priv, priv->hw);
> + if (ret)
> + return ret;
> + }
> +

I am currently working on my Memory-mapped DW XPCS patchset cooking:
https://lore.kernel.org/netdev/20231205103559.9605-1-fancer.lancer@xxxxxxxxx/
The changes in this series seems to intersect to what is/will be
introduced in my patchset. In particular as before I am going to
use the "pcs-handle" property for getting the XPCS node. If so what
about collecting PCS-related things in a single place. Like this:

int stmmac_xpcs_setup(struct net_device *ndev)
{
...

if (priv->plat->pcs_init) {
return priv->plat->pcs_init(priv); /* Romain' part */
} else if (fwnode_property_present(priv->plat->port_node, "pcs-handle")) {
/* My DW XPCS part */
} else if (priv->plat->mdio_bus_data && priv->plat->mdio_bus_data->has_xpcs) {
/* Currently implemented procedure */
}

...
}

void stmmac_xpcs_clean(struct net_device *ndev)
{
...

if (priv->plat->pcs_exit) {
priv->plat->pcs_exit(priv);
return;

}

xpcs_destroy(priv->hw->xpcs);
priv->hw->xpcs = NULL;
}

Please see the last two patches in my series:
https://lore.kernel.org/netdev/20231205103559.9605-16-fancer.lancer@xxxxxxxxx/
https://lore.kernel.org/netdev/20231205103559.9605-17-fancer.lancer@xxxxxxxxx/
as a reference of how the changes could be provided.

-Serge(y)

> /* Get the HW capability (new GMAC newer than 3.50a) */
> priv->hw_cap_support = stmmac_get_hw_features(priv);
> if (priv->hw_cap_support) {
> @@ -7290,6 +7296,12 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
> return 0;
> }
>
> +static void stmmac_hw_exit(struct stmmac_priv *priv)
> +{
> + if (priv->plat->pcs_exit)
> + priv->plat->pcs_exit(priv, priv->hw);
> +}
> +
> static void stmmac_napi_add(struct net_device *dev)
> {
> struct stmmac_priv *priv = netdev_priv(dev);
> @@ -7804,6 +7816,7 @@ int stmmac_dvr_probe(struct device *device,
> priv->hw->pcs != STMMAC_PCS_RTBI)
> stmmac_mdio_unregister(ndev);
> error_mdio_register:
> + stmmac_hw_exit(priv);
> stmmac_napi_del(ndev);
> error_hw_init:
> destroy_workqueue(priv->wq);
> @@ -7844,6 +7857,7 @@ void stmmac_dvr_remove(struct device *dev)
> if (priv->hw->pcs != STMMAC_PCS_TBI &&
> priv->hw->pcs != STMMAC_PCS_RTBI)
> stmmac_mdio_unregister(ndev);
> + stmmac_hw_exit(priv);
> destroy_workqueue(priv->wq);
> mutex_destroy(&priv->lock);
> bitmap_free(priv->af_xdp_zc_qps);
> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> index dfa1828cd756a..941fde506e514 100644
> --- a/include/linux/stmmac.h
> +++ b/include/linux/stmmac.h
> @@ -285,6 +285,8 @@ struct plat_stmmacenet_data {
> int (*crosststamp)(ktime_t *device, struct system_counterval_t *system,
> void *ctx);
> void (*dump_debug_regs)(void *priv);
> + int (*pcs_init)(struct stmmac_priv *priv, struct mac_device_info *hw);
> + void (*pcs_exit)(struct stmmac_priv *priv, struct mac_device_info *hw);
> void *bsp_priv;
> struct clk *stmmac_clk;
> struct clk *pclk;
>
> --
> 2.44.0
>
>