On Wed, Jun 21, 2017 at 04:04:44PM +0300, Gal Pressman wrote:
> Currently, drivers can only tell whether the link is up/down through
> ETHTOOL_GLINK callback, but no additional information is given in case
> of link down.
> This patch provides an infrastructure that allows drivers to hint
> the user with the reason why the link is down, in order to ease the
> debug process.
>
> Reasons are separated to two types, generic and vendor specific.
> Drivers can reply with a generic reason using the enums provided in this
> patch (and the ones that will be added in the future), which will be
> translated to strings by the userspace ethtool.
> In case of a vendor specific reason (not suitable for most vendors),
> drivers can reply with ETHTOOL_VENDOR_SPECIFIC reason, in this case the
> vendor_reason field should be filled with a vendor specific status code
> which will be parsed by the vendor specific userspace parser if one is
> available.
>
> This kind of information can save system administrators precious time
> which will not be wasted trying to understand why the link won't go
> up.
>
> For example, when the cable is unplugged:
> $ ethtool ethXX
> ...
> Link detected: no (Cable unplugged)
>
> Signed-off-by: Gal Pressman <g...@mellanox.com>
> Signed-off-by: Saeed Mahameed <sae...@mellanox.com>
> ---
> include/linux/ethtool.h | 2 ++
> include/uapi/linux/ethtool.h | 33 +++++++++++++++++++++++++++++++++
> net/core/ethtool.c | 24 ++++++++++++++++++++++++
> 3 files changed, 59 insertions(+)
>
> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
> index 83cc986..d472047 100644
> --- a/include/linux/ethtool.h
> +++ b/include/linux/ethtool.h
> @@ -374,5 +374,7 @@ struct ethtool_ops {
> struct ethtool_link_ksettings *);
> int (*set_link_ksettings)(struct net_device *,
> const struct ethtool_link_ksettings *);
> + int (*get_link_down_reason)(struct net_device *,
> + struct ethtool_link_down_reason *);
> };
> #endif /* _LINUX_ETHTOOL_H */
> diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
> index 7d4a594..8cf9d2c 100644
> --- a/include/uapi/linux/ethtool.h
> +++ b/include/uapi/linux/ethtool.h
> @@ -550,6 +550,13 @@ struct ethtool_pauseparam {
>
> #define ETH_GSTRING_LEN 32
>
> +struct ethtool_link_down_reason {
> + __u32 cmd;
> + __u32 reason;
> + __u32 vendor_reason;
> + __u32 reserved[4];
> +};
Shouldn't this be a list? The device is over its power budget,
overheating and does not have a cable plugged in. There can be
multiple reasons it is down.
Andrew
