SOLVED Realtek RTL8111/8168/8411 stops working after some time

[ooounohu]

SCENARIO:

• Linux Mint 20.3
• Lenovo IdeaPad L340 Gaming laptop with Realtek r8169 GB NIC
• Updated to Linux Kernel 5.15

PROBLEM:
Wired network would stop working minutes after boot.

TROUBLESHOOTING:
Revert to Linux Kernel 5.13, behavior resolved. Boot to Linux Mint 21 Cinnamon USB drive, behavior persists.

Found nearly identical report of behavior on Ask Ubuntu (https://askubuntu.com/questions/1405788 ... ot-working) with suggestion to install r8168-dkms, reboot and retest which worked for OP.

Installed Linux Kernel 5.15.0-43, rebooted, tested for persistent behavior, installed r8168-dkms via WiFi network, rebooted, tested, behavior resolved.

SOLUTION:
Install r8168-dkms after updating to Linux Kernel 5.15.

NOTE:
Hopefully this helps others if not a reminder for myself in the future.

[deepakdeshp]

Very good documentation. Thank you.

[hkall]

If 5.13 is ok and 5.15 fails for you, then one of the very few changes to r8169 driver between these two kernel versions should cause the issue.
I see only the following as candidate. 5.15 enables PCI ASPM L0 power-saving. You could test after disabling ASPM in BIOS. Alternative you can dynamically switch off ASPM L0 by writing 0 to /sys/class/net/<if>/device/link/l0_aspm.
Typically ASPM-related issues are system-specific (combination of R8168 chip version, mainboard chipset, BIOS).

[ooounohu]

If 5.13 is ok and 5.15 fails for you, then one of the very few changes to r8169 driver between these two kernel versions should cause the issue.
I see only the following as candidate. 5.15 enables PCI ASPM L0 power-saving. You could test after disabling ASPM in BIOS. Alternative you can dynamically switch off ASPM L0 by writing 0 to /sys/class/net/<if>/device/link/l0_aspm.
Typically ASPM-related issues are system-specific (combination of R8168 chip version, mainboard chipset, BIOS).

I did a little digging prior to discovering the Ask Ubuntu post though I'm not yet fluent in kernel speak. Honestly, my Linux game is still a bit new. That said, I did see the ASPM stuff in the kernel change log and suspected it was related. I'm favoring your suggestions so I may give them a try in the near future. Thanks! Also, I think I'm picking up what you're laying down regarding system specific issues. Perhaps I should amend my post title to be more specific to the Lenovo IdeaPad L340 Gaming device that the OP at Ask Ubuntu and I have?