Subject: Re: [PATCH 1/6] net: phy: add interface modes for XFI, SFI

From: Russell King - ARM Linux admin <[email-masked]>
Date: Thu, 19 Dec 2019 17:28:34 +0000

On Thu, Dec 19, 2019 at 05:21:16PM +0200, Madalin Bucur wrote:
> From: Madalin Bucur <[email-masked]>
> 
> Add explicit entries for XFI, SFI to make sure the device
> tree entries for phy-connection-type "xfi" or "sfi" are
> properly parsed and differentiated against the existing
> backplane 10GBASE-KR mode.

10GBASE-KR is actually used for XFI and SFI (due to a slight mistake on
my part, it should've been just 10GBASE-R).

Please explain exactly what the difference is between XFI, SFI and
10GBASE-R. I have not been able to find definitive definitions for
XFI and SFI anywhere, and they appear to be precisely identical to
10GBASE-R. It seems that it's just a terminology thing, with
different groups wanting to "own" what is essentially exactly the
same interface type.

> 
> Signed-off-by: Madalin Bucur <[email-masked]>
> ---
>  include/linux/phy.h | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index 5032d453ac66..ebb793621f0b 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -99,7 +99,8 @@ typedef enum {
>  	PHY_INTERFACE_MODE_2500BASEX,
>  	PHY_INTERFACE_MODE_RXAUI,
>  	PHY_INTERFACE_MODE_XAUI,
> -	/* 10GBASE-KR, XFI, SFI - single lane 10G Serdes */
> +	PHY_INTERFACE_MODE_XFI,
> +	PHY_INTERFACE_MODE_SFI,
>  	PHY_INTERFACE_MODE_10GKR,
>  	PHY_INTERFACE_MODE_USXGMII,
>  	PHY_INTERFACE_MODE_MAX,
> @@ -175,6 +176,10 @@ static inline const char *phy_modes(phy_interface_t interface)
>  		return "rxaui";
>  	case PHY_INTERFACE_MODE_XAUI:
>  		return "xaui";
> +	case PHY_INTERFACE_MODE_XFI:
> +		return "xfi";
> +	case PHY_INTERFACE_MODE_SFI:
> +		return "sfi";
>  	case PHY_INTERFACE_MODE_10GKR:
>  		return "10gbase-kr";
>  	case PHY_INTERFACE_MODE_USXGMII:
> -- 
> 2.1.0
> 
> 

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