Subject: Re: [RFC] ethtool: Expand ethtool_cmd.speed to 32 bits

From: Rick Jones <[email-masked]>
Date: Tue, 15 Jul 2008 14:53:16 -0700

Brandon Philips wrote:
> Introduce the speed_hi field to ethtool_cmd, using the reserved space,
> to expand the speed field to 2^32 Megabits/second.
> 
> Making this field expansion now gives us plenty of time to fix up the
> user-space pieces that use SIOCETHTOOL before hardware faster than 64
> Gb/s is available.
> 
> Signed-off-by: Brandon Philips <[email-masked]>
> 
> ---
>  include/linux/ethtool.h |   17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> Index: linux-2.6/include/linux/ethtool.h
> ===================================================================
> --- linux-2.6.orig/include/linux/ethtool.h
> +++ linux-2.6/include/linux/ethtool.h
> @@ -27,9 +27,24 @@ struct ethtool_cmd {
>  	__u8	autoneg;	/* Enable or disable autonegotiation */
>  	__u32	maxtxpkt;	/* Tx pkts before generating tx int */
>  	__u32	maxrxpkt;	/* Rx pkts before generating rx int */
> -	__u32	reserved[4];
> +	__u16	speed_hi;
> +	__u16	reserved2;
> +	__u32	reserved[3];
>  };

I certainly agree with the concept of preparing for faster NICs.  Are 
bits in that structure sufficiently precious to go the split route, or 
would it be cleaner to just grab a contiguous 32 bits from the structure?

rick jones