QNAP TS419: Wake-On-Lan not working

[Hartmut <qnap@rsxii.de>]

Hi all,

I'm running Debian 6.3.0-18 on a TS419U+ which is a huge improvement 
over the stock firmware - many thanks to all who have worked on it!

Wake-on-lan was running fine until an update. I just ran apt-get upgrade 
again, but it didn't solved the problem. Unfortunately, I cannot tell in 
which moment it stopped working. The current kernel is
   kernel 4.9.0-3-marvell #1 Debian 4.9.30-2+deb9u5 (2017-09-19)

ethtool reports wol is set, see 1) but I'm wondering why the link is not 
detected, since in the interface is active and hwinfo reports
  Link detected: yes

How can I get wol back working? It is essential, as the server is 
usually started remotely for backups.

One thing I should mention: I've attached a serial console some months 
ago which is working fine. Could this brake wol?

Many thanks,
Hartmut

--

1) Settings for eth0:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: No
        Advertised auto-negotiation: Yes
        Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                             100baseT/Half 100baseT/Full
                                             1000baseT/Half 1000baseT/Full
        Link partner advertised pause frame use: No
        Link partner advertised auto-negotiation: No
        Speed: 1000Mb/s
        Duplex: Full
        Port: MII
        PHYAD: 0
        Transceiver: external
        Auto-negotiation: on
        Supports Wake-on: g
        Wake-on: g
        Link detected: no