to pad with 0xFF when it encounter short frames. According to RFC
1042 the pad bytes should be 0x00.
Because manual padding consumes extra CPU cycles, introduce a new
tunable which controls the padding behavior. Turning this tunable
on will have driver pad manually but it's disabled by default. Users
can enable software padding by setting the following tunable to
non-zero value.
dev.sis.%d.manual_pad="1"
PR: kern/35422 (patch not used)
94222398d1