Re: [PATCH net] amd-xgbe: Avoid spurious link down messages during interface toggle

[Dawid Osuchowski <dawid.osuchowski@linux.intel.com>]

On 2025-10-10 8:51 AM, Raju Rangoju wrote:
> During interface toggle operations (ifdown/ifup), the driver currently
> resets the local helper variable 'phy_link' to -1. This causes the link
> state machine to incorrectly interpret the state as a link change event,
> resulting in spurious "Link is down" messages being logged when the
> interface is brought back up.
> 
> Preserve the phy_link state across interface toggles to avoid treating
> the -1 sentinel value as a legitimate link state transition.
> 
> Fixes: 88131a812b16 ("amd-xgbe: Perform phy connect/disconnect at dev open/stop")
> Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>

Reviewed-by: Dawid Osuchowski <dawid.osuchowski@linux.intel.com>
> ---
>   drivers/net/ethernet/amd/xgbe/xgbe-drv.c  | 1 -
>   drivers/net/ethernet/amd/xgbe/xgbe-mdio.c | 1 +
>   2 files changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> index f0989aa01855..4dc631af7933 100644
> --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> @@ -1080,7 +1080,6 @@ static void xgbe_free_rx_data(struct xgbe_prv_data *pdata)
>   
>   static int xgbe_phy_reset(struct xgbe_prv_data *pdata)
>   {
> -	pdata->phy_link = -1;
>   	pdata->phy_speed = SPEED_UNKNOWN;
>   
>   	return pdata->phy_if.phy_reset(pdata);
> diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
> index 1a37ec45e650..7675bb98f029 100644
> --- a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
> +++ b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
> @@ -1555,6 +1555,7 @@ static int xgbe_phy_init(struct xgbe_prv_data *pdata)
>   		pdata->phy.duplex = DUPLEX_FULL;
>   	}
>   
> +	pdata->phy_link = 0;
>   	pdata->phy.link = 0;

Took me a sec to spot the difference between the two :)

>   
>   	pdata->phy.pause_autoneg = pdata->pause_autoneg;