Subject: Re: [PATCH NET 2/2] net: hns: Use phy_driver to setup Phy loopback

From: Andrew Lunn <[email-masked]>
Date: Fri, 23 Jun 2017 05:20:11 +0200

On Thu, Jun 22, 2017 at 04:53:33PM +0800, Lin Yun Sheng wrote:
> Use function set_loopback in phy_driver to setup phy loopback
> when doing ethtool self test.
> 
> Signed-off-by: Lin Yun Sheng <[email-masked]>
> ---
>  drivers/net/ethernet/hisilicon/hns/hns_ethtool.c | 64 ++++--------------------
>  1 file changed, 10 insertions(+), 54 deletions(-)
> 
> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
> index e95795b..660b51e 100644
> --- a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
> +++ b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
> @@ -259,66 +259,22 @@ static int hns_nic_set_link_ksettings(struct net_device *net_dev,
>  
>  static int hns_nic_config_phy_loopback(struct phy_device *phy_dev, u8 en)
>  {
> -#define COPPER_CONTROL_REG 0
> -#define PHY_POWER_DOWN BIT(11)
> -#define PHY_LOOP_BACK BIT(14)
> -	u16 val = 0;
>  
> -	if (phy_dev->is_c45) /* c45 branch adding for XGE PHY */
> +	if (phy_dev->is_c45 || !phy_dev->drv)
> +		return -ENOTSUPP;
> +
> +	if (!phy_dev->drv->resume || !phy_dev->drv->suspend ||
> +	    !phy_dev->drv->set_loopback)
>  		return -ENOTSUPP;

No, i said to have a function is phy.c which does this check. The phy
core needs to keep track of if loopback is already enabled, and return
an error if it is attempted to turn it on twice, or disable it when it
is not enabled.

   Andrew