You must fully power OFF your computer to clear this error state. Reboot/restart and sleep are NOT sufficient.
I was able to get my Ethernet port working normally again by shutting down, unplugging AC adapter, and removing battery for a minute. When I brought the machine back up after this Ethernet port was working normally again and has been for some time now.
Before hitting upon this solution I was able to guess that this was some kind of hardware bug because my Ethernet port still didn't work even if I rebooted into Windows Vista (i.e. it was specific to Ubuntu or Linux).
I suspect that all the people above who reported switching to a different kernel solving their problem may have done a shutdown and that is what "fixed" their issue rather than the different kernel itself.
Hope this helps anyone else coming here with the same problem.
I believe I found a solution to this problem:
You must fully power OFF your computer to clear this error state. Reboot/restart and sleep are NOT sufficient.
I was able to get my Ethernet port working normally again by shutting down, unplugging AC adapter, and removing battery for a minute. When I brought the machine back up after this Ethernet port was working normally again and has been for some time now.
Before hitting upon this solution I was able to guess that this was some kind of hardware bug because my Ethernet port still didn't work even if I rebooted into Windows Vista (i.e. it was specific to Ubuntu or Linux).
I suspect that all the people above who reported switching to a different kernel solving their problem may have done a shutdown and that is what "fixed" their issue rather than the different kernel itself.
Hope this helps anyone else coming here with the same problem.