Subject: e1000e max frame calculation

From: Michael Cronenworth <[email-masked]>
Date: Mon, 06 Apr 2015 11:38:29 -0500

Hello,

I have attempted to discuss this with upstream directly[1], but they will not 
respond to me. I will now attempt here.

The e1000e driver uses a different maximum frame calculation after a commit[2] in 
kernel 3.15. This caused everyone's setups that were using 9000 for MTU to break 
after they rebooted on their kernel update. The addition of the VLAN bytes force 
users to use 8996.

Other drivers appear to be using the "old" maximum frame calculation and can 
continue to use 9000.

Can a standard be decided upon that all drivers use or is it acceptable that one 
driver "does its own thing?"

Thanks,
Michael

[1] https://sourceforge.net/p/e1000/bugs/459/
[2] 
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/net/ethernet/intel/e1000e/netdev.c?id=c751a3d58cf2dae89ec941a259025b0175d67b0c