Boot method: SD-card
Image version: https://ftp.debian.org/debian/dists/stable/main/installer-armhf/current/images/hd-media/SD-card-images/
Date: 2025-05-15

Machine: Olimex A20-OLinuXino-LIME2 rev C

Base System Installation Checklist:
[O] = OK, [E] = Error (please elaborate below), [ ] = didn't try it

Initial boot:           [O]
Detect network card:    [O]
Configure network:      [O]
Detect media:           [O]
Load installer modules: [O]
Clock/timezone setup:   [O]
User/password setup:    [O]
Detect hard drives:     [O]
Partition hard drives:  [O]
Install base system:    [O]
Install tasks:          [O]
Install boot loader:    [O]
Overall install:        [E]

Comments/Problems:

This is about Debian *stable*, not testing. I did not find a bug report about
this issue, so I thought I would file one to leave a trace.

Every thing went fine during the installation.

However, after booting the installed system, ethernet randomly fails to be
detected after boot (after some boots it works, after some it doesn't). Even if
a cable is plugged, no network leds light up. When this happen, one can simply
'ip link set dev end0 down ; sleep 1 ; ip link set dev end0 up' to restore
normal behaviour.

This is the initial detection of the NIC:
[   18.400578] sun7i-dwmac 1c50000.ethernet end0: Register MEM_TYPE_PAGE_POOL RxQ-0
[   18.403906] sun7i-dwmac 1c50000.ethernet end0: PHY [stmmac-0:01] driver [RTL8211B Gigabit Ethernet] (irq=POLL)
[   18.412663] sun7i-dwmac 1c50000.ethernet end0: No Safety Features support found
[   18.412708] sun7i-dwmac 1c50000.ethernet end0: RX IPC Checksum Offload disabled
[   18.412742] sun7i-dwmac 1c50000.ethernet end0: No MAC Management Counters available
[   18.412759] sun7i-dwmac 1c50000.ethernet end0: PTP not supported by HW
[   18.425423] sun7i-dwmac 1c50000.ethernet end0: configuring for phy/rgmii-id link mode

And this is one is after the down/up trick as described above.
[   63.739594] sun7i-dwmac 1c50000.ethernet end0: Register MEM_TYPE_PAGE_POOL RxQ-0
[   63.743553] sun7i-dwmac 1c50000.ethernet end0: PHY [stmmac-0:01] driver [RTL8211B Gigabit Ethernet] (irq=POLL)
[   63.753716] sun7i-dwmac 1c50000.ethernet end0: No Safety Features support found
[   63.753789] sun7i-dwmac 1c50000.ethernet end0: RX IPC Checksum Offload disabled
[   63.753837] sun7i-dwmac 1c50000.ethernet end0: No MAC Management Counters available
[   63.753884] sun7i-dwmac 1c50000.ethernet end0: PTP not supported by HW
[   63.753965] sun7i-dwmac 1c50000.ethernet end0: configuring for phy/rgmii-id link mode
[   66.822512] sun7i-dwmac 1c50000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[   66.822807] IPv6: ADDRCONF(NETDEV_CHANGE): end0: link becomes ready

(...)

I also faced this issue but was lazy. It may be related with this but I
haven't investigated:

<https://linux-sunxi.org/Olimex_A20-OLinuXino-Lime2#GMAC_quirks>

Or unplug and re-plug the ethernet cable.

Unplugging/re-plugging the network cable is another way to make it work
again.

Debian 13 is also affected.

Lucas