mskc0: Tx descriptor error

[Lhunath (Maarten B.)]

>> e1000phy0: <Marvell 88E1149 Gigabit PHY> PHY 0 on miibus0
>> e1000phy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
> 
> I guess you hit known msk(4) issue for 88E8056/88E1149 PHY. Some
> users have no problems but others seem to suffer from the issue.
> There is also a PR about this but it seems it's hard to fix that
> mainly because I don't have access to the hardware.

Perhaps if you can provide patches against the 8.0-REL msk(1) to make it extremely verbose, I could provide the output and we might learn more about the cause of this issue.  The fact that it's so easily reproduced must play in favor.

I'm afraid I simply have not got the time and resources to learn about both the FreeBSD kernel + module writing and network interface driver operations.  The only alternative would be to wait until somebody that does happens upon this hardware.