Subject: Re: [PATCH] MACB: Set PHY address in kernel parameters

From: Patrick McHardy <[email-masked]>
Date: Wed, 31 Mar 2010 10:28:58 +0200

Anders Darander wrote:
> From: Anders Darander <[email-masked]>
> 
> Add the possibility to set the phy address. This is needed if an integrated
> switch is connected to the MAC, as it is often the case that the highest port
> is the one connected to the MAC of the MCU.
> 
> E.g. in the case of the Micrel KSZ8873, port 3 is the one to connect to the
> MCU, thus, the MAC needs to connect to phy address 0x03, instead of the first
> phy found.
> 
> Signed-off-by: Anders Darander <[email-masked]>
> ---
>  drivers/net/macb.c |   14 +++++++++++++-
>  1 files changed, 13 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> index c8a18a6..9b4e301 100644
> --- a/drivers/net/macb.c
> +++ b/drivers/net/macb.c
> @@ -53,6 +53,14 @@
>  #define MACB_RX_INT_FLAGS	(MACB_BIT(RCOMP) | MACB_BIT(RXUBR)	\
>  				 | MACB_BIT(ISR_ROVR))
>  
> +/*
> + * Setup PHY probeing
> + */
> +
> +static int phy_addr = PHY_MAX_ADDR;
> +module_param(phy_addr, ushort, 0);
> +MODULE_PARAM_DESC(phy_addr, "PHY address connected to the MACB");
> +
>  static void __macb_set_hwaddr(struct macb *bp)
>  {
>  	u32 bottom;
> @@ -193,7 +201,11 @@ static int macb_mii_probe(struct net_device *dev)
>  	struct eth_platform_data *pdata;
>  	int ret;
>  
> -	phydev = phy_find_first(bp->mii_bus);
> +	if (phy_addr >= PHY_MAX_ADDRESS)
> +		phydev = phy_find_first(bp->mii_bus);
> +	else
> +		phydev = bp->mii_bus->phy_map[phy_addr];

This looks like you need to use an unsigned to avoid negative
indices.