Subject: Re: [PATCHv2 (net.git) 2/2] stmmac: fix MDIO settings

From: Phil Reid <[email-masked]>
Date: Fri, 11 Mar 2016 16:16:44 +0800

G'day Giuseppe,

Sorry for delay in responding.
I feel responsible for starting the changes breaking this.

See below.

On 11/03/2016 3:44 PM, Giuseppe Cavallaro wrote:
> Initially the phy_bus_name was added to manipulate the
> driver name but It was recently just used to manage the
> fixed-link and then to take some decision at run-time
> inside the main (for example to skip EEE).
> So the patch uses the is_pseudo_fixed_link and removes
> removes the phy_bus_name variable not necessary anymore.
>
> The driver can manage the mdio registration by using phy-handle,
> dwmac-mdio and own parameter e.g. snps,phy-addr.
> This patch takes care about all these possible configurations
> and fixes the mdio registration in case of there is a real
> transceiver or a switch (that needs to be managed by using
> fixed-link).
>
> Signed-off-by: Giuseppe Cavallaro <[email-masked]>
> Reviewed-by: Andreas Färber <[email-masked]>
> Tested-by: Frank Schäfer <[email-masked]>
> Cc: Gabriel Fernandez <[email-masked]>
> Cc: Dinh Nguyen <[email-masked]>
> Cc: David S. Miller <[email-masked]>
> ---
>
> V2: use is_pseudo_fixed_link
>
>   drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  |   11 +++--------
>   .../net/ethernet/stmicro/stmmac/stmmac_platform.c  |   14 +++++---------
>   include/linux/stmmac.h                             |    1 -
>   3 files changed, 8 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index c21015b..389d7d0 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -271,7 +271,6 @@ static void stmmac_eee_ctrl_timer(unsigned long arg)
>    */
>   bool stmmac_eee_init(struct stmmac_priv *priv)
>   {
> -	char *phy_bus_name = priv->plat->phy_bus_name;
>   	unsigned long flags;
>   	bool ret = false;
>
> @@ -283,7 +282,7 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
>   		goto out;
>
>   	/* Never init EEE in case of a switch is attached */
> -	if (phy_bus_name && (!strcmp(phy_bus_name, "fixed")))
> +	if (priv->phydev->is_pseudo_fixed_link)
>   		goto out;
>
>   	/* MAC core supports the EEE feature. */
> @@ -820,12 +819,8 @@ static int stmmac_init_phy(struct net_device *dev)
>   		phydev = of_phy_connect(dev, priv->plat->phy_node,
>   					&stmmac_adjust_link, 0, interface);
>   	} else {
> -		if (priv->plat->phy_bus_name)
> -			snprintf(bus_id, MII_BUS_ID_SIZE, "%s-%x",
> -				 priv->plat->phy_bus_name, priv->plat->bus_id);
> -		else
> -			snprintf(bus_id, MII_BUS_ID_SIZE, "stmmac-%x",
> -				 priv->plat->bus_id);
> +		snprintf(bus_id, MII_BUS_ID_SIZE, "stmmac-%x",
> +			 priv->plat->bus_id);
>
>   		snprintf(phy_id_fmt, MII_BUS_ID_SIZE + 3, PHY_ID_FMT, bus_id,
>   			 priv->plat->phy_addr);
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 6a52fa1..ed33920 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -138,7 +138,11 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>   			return ERR_PTR(-ENODEV);
>
>   		plat->phy_node = of_node_get(np);
> -	}
> +	} else
> +		plat->mdio_bus_data =
> +			devm_kzalloc(&pdev->dev,
> +				     sizeof(struct stmmac_mdio_bus_data),
> +				     GFP_KERNEL);

This breaks my use case where I have a fixed link but also need the mdio bus for
talking to a dsa switch. stmmac_mdio_register bails out because mdio_bus_data is
never allocated here at this point when a fixed link exists with no phy-handle
property. Removing the else solves my use.

Possibly it could be allocated in stmmac_mdio_register if snps,dwmac-mdio
is found and not already allocated.
With the
	if (!mdio_bus_data)
		return 0;
to after the device tree query.

>
>   	/* "snps,phy-addr" is not a standard property. Mark it as deprecated
>   	 * and warn of its use. Remove this when phy node support is added.
> @@ -146,14 +150,6 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>   	if (of_property_read_u32(np, "snps,phy-addr", &plat->phy_addr) == 0)
>   		dev_warn(&pdev->dev, "snps,phy-addr property is deprecated\n");
>
> -	if ((plat->phy_node && !of_phy_is_fixed_link(np)) || plat->phy_bus_name)
> -		plat->mdio_bus_data = NULL;
> -	else
> -		plat->mdio_bus_data =
> -			devm_kzalloc(&pdev->dev,
> -				     sizeof(struct stmmac_mdio_bus_data),
> -				     GFP_KERNEL);
> -
>   	of_property_read_u32(np, "tx-fifo-depth", &plat->tx_fifo_size);
>
>   	of_property_read_u32(np, "rx-fifo-depth", &plat->rx_fifo_size);
> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> index eead8ab..1b4884c 100644
> --- a/include/linux/stmmac.h
> +++ b/include/linux/stmmac.h
> @@ -94,7 +94,6 @@ struct stmmac_dma_cfg {
>   };
>
>   struct plat_stmmacenet_data {
> -	char *phy_bus_name;
>   	int bus_id;
>   	int phy_addr;
>   	int interface;
>

-- 
Regards
Phil Reid