Subject: Re: [PATCH 1/3] net: phy: add support to detect 100BASE-T1 capability

From: Andrew Lunn <[email-masked]>
Date: Wed, 13 Dec 2017 21:11:10 +0100

On Wed, Dec 13, 2017 at 06:37:49PM +0100, Lucas Stach wrote:
> 100BASE-T1 is the automotive ethernet standard 802.3bw-2015. Currently
> we don't detect any valid modes for PHYs, which only support this
> standard. Add support to detect the common 100Mbit full-duplex mode.
> 
> Signed-off-by: Lucas Stach <[email-masked]>
> ---
>  drivers/net/phy/phy_device.c | 2 ++
>  include/uapi/linux/mii.h     | 1 +
>  2 files changed, 3 insertions(+)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 67f25ac29025..8ef48b38d97b 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -1607,6 +1607,8 @@ int genphy_config_init(struct phy_device *phydev)
>  		if (val < 0)
>  			return val;
>  
> +		if (val & ESTATUS_100T1_FULL)
> +			features |= SUPPORTED_100baseT_Full;

Hi Lucas

Why did you decide to do this, and not add a SUPPORTED_100baseT1?

Could a device support both 100-BASE-T and 100-BASE-T1?  If at some
point we need to differentiate between them, it is going to be
hard. Especially since this is part of the kernel ABI.

      Andrew