Problems with em0 driver after upgrade to r303832

[Pete French]

> > I thought it was the physical card, but I have swapped this out
> > for a completely different one and the problems remain.
>
> What does pciconf -lvb display for the PCI IDs for this card ?

I have just dropped a third card into the machine 9I need
to get some work done unfortnately) - for this the output is 

em0 at pci0:3:2:0: class=0x020000 card=0x13768086 chip=0x107c8086 rev=0x05 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = '82541PI Gigabit Ethernet Controller'
    class      = network
    subclass   = ethernet
    bar   [10] = type Memory, range 32, base 0xfebc0000, size 131072, enabled
    bar   [14] = type Memory, range 32, base 0xfeba0000, size 131072, enabled
    bar   [18] = type I/O Port, range 32, base 0xe400, size 64, enabled

I will let you know if it locks up, or if it doesnt -I swapped
PCI slots as well in case this is actually a hardware issue.

> If you use r303832, this is CURRENT (12.x) ? Then maybe the
> question should be discussed on current at freebsd.org.

Its 10.3-STABLE according to uname -a

-pete.