Re: [PATCH net-next 2/3] dt-bindings: net: cdns,macb: Add wol-arp-packet property

[Vineeth Karumanchi]

Hi Andrew, Krzysztof,



On 31/01/24 6:48 pm, Andrew Lunn wrote:
> On Wed, Jan 31, 2024 at 01:09:19PM +0530, Vineeth Karumanchi wrote:
> > Hi Andrew,
> >
> >
> > On 31/01/24 6:56 am, Andrew Lunn wrote:
> > > On Tue, Jan 30, 2024 at 04:18:44PM +0530, Vineeth Karumanchi wrote:
> > > > "wol-arp-packet" property enables WOL with ARP packet.
> > > > It is an extension to "magic-packet for WOL.
> > >
> > > It not clear why this is needed. Is this not a standard feature of the
> > > IP? Is there no hardware bit indicating the capability?
> >
> > WOL via both ARP and Magic packet is supported by the IP version on ZU+ and
> > Versal. However, user can choose which type of packet to recognize as a WOL
> > event - magic packet or ARP.
>
> ethtool says:
>
>             wol p|u|m|b|a|g|s|f|d...
>                    Sets Wake-on-LAN options.  Not all devices support this.  The argument to this  option  is  a
>                    string of characters specifying which options to enable.
>                    p   Wake on PHY activity
>                    u   Wake on unicast messages
>                    m   Wake on multicast messages
>                    b   Wake on broadcast messages
>                    a   Wake on ARP
>                    g   Wake on MagicPacket™
>                    s   Enable SecureOn™ password for MagicPacket™
>                    f   Wake on filter(s)
>                    d   Disable  (wake  on  nothing).  This option
>                        clears all previous options.
>
> So why do we need a DT property?

The earlier implementation of WOL (magic-packet) was using DT property.
We added one more packet type using DT property to be in-line with the 
earlier implementation.

However, I echo with you that this feature should be in driver (CAPS).
We will re-work the implementation with the below flow:

- Add MACB_CAPS_WOL capability to the supported platforms
- Advertise supported WOL packet types based on the CAPS in ethtool.
- Users can set packet type using ethtool.

Please let me know your thoughts/suggestions.

🙏 vineeth

> 	Andrew