not allow multicast filter programming when controller is busy to
send/receive frames. So it used to mark need_mcsetup bit and defer
multicast filter programming until controller becomes idle state.
To detect when the controller is idle fxp(4) relied on Tx
completion interrupt with NOP command and fxp_start_body and
fxp_intr_body had to see whether pending multicast filter
programming was requested. This resulted in very complex logic and
sometimes it did not work as expected.
Since the controller should be in idle state before any multicast
filter modifications I changed it to reinitialize the controller
whenever multicast filter programming is required. This is the same
way what OpenBSD and NetBSD does. Also I added IFF_DRV_RUNNING
check in ioctl handler so controller would be reinitialized only if
it is absolutely needed.
With this change I guess we can remove fxp(4) DELAY hack in ifioctl
for IPv6 case.
7cc34cc935