[Powertop] Idle power consumption of Intel e1000e kernel module

Hi,

On my ThinkPad T440s, PowerTOP-2.5 shows that the e1000e kernel module
is drawing considerable amount of power when not it use (cable unplugged):

> The battery reports a discharge rate of 5.86 W
> The estimated remaining time is 5 hours, 11 minutes
> 
> Summary: 143.9 wakeups/second,  10.9 GPU ops/seconds, 0.0 VFS ops/sec and 2.7% CPU use
> 
> Power est.              Usage       Events/s    Category       Description
>   3.76 W     49.0%                      Device         Display backlight
>   1.46 W      0.0 pkts/s                Device         Network interface: eth0 (e1000e)

What I observed is that, if I remove the e1000e kernel module with
`rmmod e1000e`, the corresponding entry in PowerTOP is gone, but the
battery discharge rate stays the same.  So, I am guessing there is
either a hardware short-circuit somewhere on the motherboard or a bug in
the underlying power management software or an estimation error.  Any
hints on how I can confirm/debug this?

Thanks,
Sree