Re: [PATCH net-next 1/3] net: phy: phylink: ensure the carrier is off when starting phylink

[Russell King - ARM Linux <linux@armlinux.org.uk>]

On Wed, Sep 19, 2018 at 11:39:31AM +0200, Antoine Tenart wrote:
> Phylink made an assumption about the carrier state being down when
> calling phylink_start(). If this assumption isn't satisfied, the
> internal phylink state could misbehave and a net device could end up not
> being functional.
> 
> This patch fixes this by explicitly calling netif_carrier_off() in
> phylink_start().
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>

Acked-by: Russell King <rmk+kernel@armlinux.org.uk>

Thanks.

> ---
>  drivers/net/phy/phylink.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index 3ba5cf2a8a5f..1d01e0c625a5 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -901,6 +901,9 @@ void phylink_start(struct phylink *pl)
>  		    phylink_an_mode_str(pl->link_an_mode),
>  		    phy_modes(pl->link_config.interface));
>  
> +	/* Always set the carrier off */
> +	netif_carrier_off(pl->netdev);
> +
>  	/* Apply the link configuration to the MAC when starting. This allows
>  	 * a fixed-link to start with the correct parameters, and also
>  	 * ensures that we set the appropriate advertisement for Serdes links.
> -- 
> 2.17.1
> 

-- 
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