vge(4) hardwares poll media status and generates an interrupt

whenever the link state is changed.  Using software based polling
for media status tracking is known to cause MII access failure
under certain conditions once link is established so vge(4) used to
rely on link status change interrupt.
However DEVICE_POLLING completely disables generation of all kind
of interrupts on vge(4) such that this resulted in not detecting
link state change event.  This means vge(4) does not correctly
detect established/lost link with DEVICE_POLLING.  Losing the
interrupt made vge(4) not to send any packets to peer since vge(4)
does not try to send any packets when there is no established link.

Work around the issue by generating link state change interrupt
with DEVICE_POLLING.

PR:		kern/160442
Approved by:	re (kib)

0 files changed, 0 insertions, 0 deletions