Thanks to @Sebastian for the dmesg output of original hirsute kernel and mine. I'll look into why the netif_running get false result during resume. Will build some customized kernel and still need your help for verification.
** Attachment added: "5.11.0-22-generic.dmesg.txt" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1931301/+attachment/5509551/+files/5.11.0-22-generic.dmesg.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1931301 Title: NIC unavailable after suspend to RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1931301/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs