linux-kernel - Re: [PATCH net-next v2 05/14] net: mvpp2: do not force the link mode

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Date:   Fri, 25 Aug 2017 23:43:13 +0100
From:   Russell King - ARM Linux <linux@...linux.org.uk>
To:     Antoine Tenart <antoine.tenart@...e-electrons.com>
Cc:     davem@...emloft.net, kishon@...com, andrew@...n.ch,
        jason@...edaemon.net, sebastian.hesselbarth@...il.com,
        gregory.clement@...e-electrons.com,
        thomas.petazzoni@...e-electrons.com, nadavh@...vell.com,
        linux-kernel@...r.kernel.org, mw@...ihalf.com, stefanc@...vell.com,
        miquel.raynal@...e-electrons.com, netdev@...r.kernel.org
Subject: Re: [PATCH net-next v2 05/14] net: mvpp2: do not force the link mode

On Fri, Aug 25, 2017 at 04:48:12PM +0200, Antoine Tenart wrote:
> The link mode (speed, duplex) was forced based on what the phylib
> returns. This should not be the case, and only forced by ethtool
> functions manually. This patch removes the link mode enforcement from
> the phylib link_event callback.

So how does RGMII work (which has no in-band signalling between the PHY
and MAC)?

phylib expects the network driver to configure it according to the PHY
state at link_event time - I think you need to explain more why you
think that this is not necessary.

> 
> Signed-off-by: Antoine Tenart <antoine.tenart@...e-electrons.com>
> ---
>  drivers/net/ethernet/marvell/mvpp2.c | 24 ------------------------
>  1 file changed, 24 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
> index fab231858a41..498a4969dc58 100644
> --- a/drivers/net/ethernet/marvell/mvpp2.c
> +++ b/drivers/net/ethernet/marvell/mvpp2.c
> @@ -5741,30 +5741,10 @@ static void mvpp2_link_event(struct net_device *dev)
>  	struct mvpp2_port *port = netdev_priv(dev);
>  	struct phy_device *phydev = dev->phydev;
>  	int status_change = 0;
> -	u32 val;
>  
>  	if (phydev->link) {
>  		if ((port->speed != phydev->speed) ||
>  		    (port->duplex != phydev->duplex)) {
> -			u32 val;
> -
> -			val = readl(port->base + MVPP2_GMAC_AUTONEG_CONFIG);
> -			val &= ~(MVPP2_GMAC_CONFIG_MII_SPEED |
> -				 MVPP2_GMAC_CONFIG_GMII_SPEED |
> -				 MVPP2_GMAC_CONFIG_FULL_DUPLEX |
> -				 MVPP2_GMAC_AN_SPEED_EN |
> -				 MVPP2_GMAC_AN_DUPLEX_EN);
> -
> -			if (phydev->duplex)
> -				val |= MVPP2_GMAC_CONFIG_FULL_DUPLEX;
> -
> -			if (phydev->speed == SPEED_1000)
> -				val |= MVPP2_GMAC_CONFIG_GMII_SPEED;
> -			else if (phydev->speed == SPEED_100)
> -				val |= MVPP2_GMAC_CONFIG_MII_SPEED;
> -
> -			writel(val, port->base + MVPP2_GMAC_AUTONEG_CONFIG);
> -
>  			port->duplex = phydev->duplex;
>  			port->speed  = phydev->speed;
>  		}
> @@ -5782,10 +5762,6 @@ static void mvpp2_link_event(struct net_device *dev)
>  
>  	if (status_change) {
>  		if (phydev->link) {
> -			val = readl(port->base + MVPP2_GMAC_AUTONEG_CONFIG);
> -			val |= (MVPP2_GMAC_FORCE_LINK_PASS |
> -				MVPP2_GMAC_FORCE_LINK_DOWN);
> -			writel(val, port->base + MVPP2_GMAC_AUTONEG_CONFIG);
>  			mvpp2_egress_enable(port);
>  			mvpp2_ingress_enable(port);
>  		} else {
> -- 
> 2.13.5
> 

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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