linux-kernel - Re: [PATCH net-next v3 2/5] net: stmmac: introduce pcs_init/pcs

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Message-ID: <42chuecdt7dpgm6fcrtt2crifvv5hflmtnmdrw5fvk3r7pwjgu@hlcv56dbeosf>
Date: Tue, 16 Apr 2024 16:41:33 +0300
From: Serge Semin <fancer.lancer@...il.com>
To: Romain Gantois <romain.gantois@...tlin.com>
Cc: "David S. Miller" <davem@...emloft.net>, 
	Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>, 
	Geert Uytterhoeven <geert+renesas@...der.be>, Magnus Damm <magnus.damm@...il.com>, 
	Alexandre Torgue <alexandre.torgue@...s.st.com>, Jose Abreu <joabreu@...opsys.com>, 
	Maxime Coquelin <mcoquelin.stm32@...il.com>, Russell King <linux@...linux.org.uk>, 
	Clément Léger <clement.leger@...tlin.com>, Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
	netdev@...r.kernel.org, devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-renesas-soc@...r.kernel.org, linux-stm32@...md-mailman.stormreply.com, 
	linux-arm-kernel@...ts.infradead.org, "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>, 
	Maxime Chevallier <maxime.chevallier@...tlin.com>
Subject: Re: [PATCH net-next v3 2/5] net: stmmac: introduce pcs_init/pcs_exit
 stmmac operations

Hi Romain, Russell

On Mon, Apr 15, 2024 at 11:18:42AM +0200, Romain Gantois wrote:
> From: "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
> 
> 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@...linux.org.uk>
> Reviewed-by: Maxime Chevallier <maxime.chevallier@...tlin.com>
> Signed-off-by: Romain Gantois <romain.gantois@...tlin.com>
> ---
>  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@gmail.com/
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@gmail.com/
https://lore.kernel.org/netdev/20231205103559.9605-17-fancer.lancer@gmail.com/
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
> 
>