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

[Andrew Lunn]

On Thu, Feb 01, 2024 at 12:11:15PM +0530, Vineeth Karumanchi wrote:
> 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.

I can understand that. It also suggests we did a bad job reviewing
that patch, and should of rejected it. But it was added a long time
ago, and we were less strict back then.

> 
> 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.

Yes, this sounds good. Maybe add to that, mark magic-packet
deprecated, and a comment that ethtool should be used instead.

Thanks
	Andrew