Andi Kleen wrote:

quoted

The problem with ethtool is that it's a non-obvious nerd knob.  At
the least the ethtool documentation should be updated to indicate that 
activating TSO effects tc accuracy.

TSO tends to be activated by default in the driver; very few people who use it
do even know that ethtool exist or what TSO is.

Indeed. As an example of an unknowing user, this discussion made me
check whether my cablemodem device (on which I'm using HFSC) uses
TSO :)