Subject: Re: [PATCH net-next v2 04/10] net: dsa: lan9303: Added adjust_link() method

From: Andrew Lunn <[email-masked]>
Date: Wed, 26 Jul 2017 19:09:28 +0200

On Tue, Jul 25, 2017 at 06:15:47PM +0200, Egil Hjelmeland wrote:
> This makes the driver react to device tree "fixed-link" declaration
> on CPU port.
> 
> - turn off autonegotiation
> - force speed 10 or 100 mb/s
> - force duplex mode
> 
> Signed-off-by: Egil Hjelmeland <[email-masked]>
> ---
>  drivers/net/dsa/lan9303-core.c | 33 +++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
> index 0806a0684d55..be6d78f45a5f 100644
> --- a/drivers/net/dsa/lan9303-core.c
> +++ b/drivers/net/dsa/lan9303-core.c
> @@ -17,6 +17,7 @@
>  #include <linux/regmap.h>
>  #include <linux/mutex.h>
>  #include <linux/mii.h>
> +#include <linux/phy.h>
>  
>  #include "lan9303.h"
>  
> @@ -746,6 +747,37 @@ static int lan9303_phy_write(struct dsa_switch *ds, int phy, int regnum,
>  	return chip->ops->phy_write(chip, phy, regnum, val);
>  }
>  
> +static void lan9303_adjust_link(struct dsa_switch *ds, int port,
> +				struct phy_device *phydev)
> +{
> +	struct lan9303 *chip = ds->priv;
> +
> +	int ctl, res;
> +
> +	ctl = lan9303_phy_read(ds, port, MII_BMCR);
> +
> +	if (!phy_is_pseudo_fixed_link(phydev))
> +		return;
> +

Hi Egil

Maybe do this check before reading MII_BMCR?

> +	ctl &= ~BMCR_ANENABLE;

Should this also mask out BMCR_SPEED100 and DUPLEX_FULL? Otherwise how
do you select 10/Half if it is already configured for 100/Full?

> +	if (phydev->speed == SPEED_100)
> +		ctl |= BMCR_SPEED100;
> +
> +	if (phydev->duplex == DUPLEX_FULL)
> +		ctl |= BMCR_FULLDPLX;
> +
> +	res =  lan9303_phy_write(ds, port, MII_BMCR, ctl);
> +
> +	if (port == chip->phy_addr_sel_strap) {
> +		/* Virtual Phy: Remove Turbo 200Mbit mode */
> +		lan9303_read(chip->regmap, LAN9303_VIRT_SPECIAL_CTRL, &ctl);
> +
> +		ctl &= ~(1 << 10); // TURBO BIT

BIT(10), or better still something like BIT(LAN9303_VIRT_SPECIAL_TURBO)

> +		res =  regmap_write(chip->regmap,
> +				    LAN9303_VIRT_SPECIAL_CTRL, ctl);
> +	}
> +}

  Andrew