PoE Mezzanine *data* not operable after update

Hi all,

It seems the PoE mezzanine (Ethernet Card - 96Boards) breaks after running updates after a fresh install of Linaro Debian. The device works in the live installer environment as well as booting from MMC after a fresh install. When it stops working the device will still receive power from the PoE interface, the kernel module loads and the OS recognizes the device, but it will not take an IP (oddly wlan0 is also missing, but I’m less concerned about that at the moment).

root@linaro-alip:~# ifconfig
eth0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 7e:45:da:56:c1:5b  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

root@linaro-alip:~# dhclient -v eth0
Internet Systems Consortium DHCP Client 4.3.5
Copyright 2004-2016 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/7e:45:da:56:c1:5b
Sending on   LPF/eth0/7e:45:da:56:c1:5b
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 18
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 21
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

It would seem that the DHCP server is simply not offering an address, but other devices as well as a USB NIC on this device (as well as it working prior to update) verifies the network is functional. The kernel is loading the module for the Ethernet controller, which is a LAN7850 from Microchip according to the device’s page above.

root@linaro-alip:~# lsmod
Module                  Size  Used by
microchip              16384  1
lan78xx                61440  0
crc32_ce               16384  0
qmi_helpers            24576  0
mdt_loader             16384  0
snd_soc_lpass_apq8016    16384  0
snd_soc_lpass_cpu      16384  1 snd_soc_lpass_apq8016
snd_soc_lpass_platform    16384  1 snd_soc_lpass_cpu
snd_soc_msm8916_digital    36864  0
snd_soc_apq8016_sbc    16384  0
rtc_pm8xxx             16384  1
snd_soc_msm8916_analog    40960  0
msm_rng                16384  0
rng_core               20480  1 msm_rng
rpmsg_char             16384  0
media                  45056  0
i2c_qcom_cci           16384  0

Then we have this from dmesg:

root@linaro-alip:~# dmesg|grep -i lan78
[    9.869006] libphy: lan78xx-mdiobus: probed
[    9.961286] usbcore: registered new interface driver lan78xx
[   10.639981] lan78xx 1-1.3:1.0 eth0: kevent 4 may have been dropped

I’m not sure what “kevent 4 may have been dropped” is related to. Googling reveals there is an ongoing issue with the RPi devices that use this NIC and attempt to update, but the going solution doesn’t seem applicable (the RPi device crashes on boot so booting without CAT5 seems to work).

It’s understood that I can place the kernel package on hold to prevent an upgrade, but I would like to use the most up-to-date kernel if possible.

Has anyone run into this issue or have any possible solutions for using this PoE board with the latest kernel? I’ll be happy to provide additional info if necessary.

To use most up-to-date kernel refer this post.

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