I do not know why the message is occurred repeatedly. I studied sk article but I did not found article about it.
Can I know the reason ? If you need version info and device info, I wrote down below.
device : SG5600
version : R80.10
hotfix : no applied
Sep 5 02:27:39 2018 smartfw3 kernel: e1000e 0000:04:00.0: eth2: Detected Hardware Unit Hang:
Sep 5 02:27:39 2018 smartfw3 kernel: TDH <1c1>
Sep 5 02:27:39 2018 smartfw3 kernel: TDT <1c3>
Sep 5 02:27:39 2018 smartfw3 kernel: next_to_use <1c3>
Sep 5 02:27:39 2018 smartfw3 kernel: next_to_clean <1c1>
Sep 5 02:27:39 2018 smartfw3 kernel: buffer_info[next_to_clean]:
Sep 5 02:27:39 2018 smartfw3 kernel: time_stamp <d2e1d774>
Sep 5 02:27:39 2018 smartfw3 kernel: next_to_watch <1c1>
Sep 5 02:27:39 2018 smartfw3 kernel: jiffies <d2e1ddd7>
Sep 5 02:27:39 2018 smartfw3 kernel: next_to_watch.status <0>
Sep 5 02:27:39 2018 smartfw3 kernel: MAC Status <80783>
Sep 5 02:27:39 2018 smartfw3 kernel: PHY Status <796d>
Sep 5 02:27:39 2018 smartfw3 kernel: PHY 1000BASE-T Status <3800>
Sep 5 02:27:39 2018 smartfw3 kernel: PHY Extended Status <3000>
Sep 5 02:27:39 2018 smartfw3 kernel: PCI Status <10>
Sep 5 05:54:02 2018 smartfw3 kernel: e1000e 0000:04:00.0: eth2: Detected Hardware Unit Hang:
Sep 5 05:54:02 2018 smartfw3 kernel: TDH <339>
Sep 5 05:54:02 2018 smartfw3 kernel: TDT <33b>
Sep 5 05:54:02 2018 smartfw3 kernel: next_to_use <33b>
Sep 5 05:54:02 2018 smartfw3 kernel: next_to_clean <339>
Sep 5 05:54:02 2018 smartfw3 kernel: buffer_info[next_to_clean]:
Sep 5 05:54:02 2018 smartfw3 kernel: time_stamp <d39ed278>
Sep 5 05:54:02 2018 smartfw3 kernel: next_to_watch <339>
Sep 5 05:54:02 2018 smartfw3 kernel: jiffies <d39ed871>
Sep 5 05:54:02 2018 smartfw3 kernel: next_to_watch.status <0>
Sep 5 05:54:02 2018 smartfw3 kernel: MAC Status <80783>
Sep 5 05:54:02 2018 smartfw3 kernel: PHY Status <796d>
Sep 5 05:54:02 2018 smartfw3 kernel: PHY 1000BASE-T Status <3800>
Sep 5 05:54:02 2018 smartfw3 kernel: PHY Extended Status <3000>
Sep 5 05:54:02 2018 smartfw3 kernel: PCI Status <10>