Symptoms: system would crash with "data modified on free list" pool
panic from the mbuf cluster pool shortly after a resume. The cluster
in question contained a valid 82557 receive descriptor and an IP
packet. Happened sporadically in normal use. Easiest way for me to
reproduce it was to run tcpdump and a flood ping and do a
suspend/resume cycle or two.
Changes:
- in interrupt handler, if the interface isn't in IFF_RUNNING state,
just ack interrupts and return; don't try to receive packets, queue
new descriptors, etc., etc.,
- add power control hook to take interface down on suspend,
and restart it (if it was up) on resume.
- tweaks to fxp_stop and fxp_shutdown to avoid recursive panics due
to the (now fixed) bug.
anyway, take advantage of this and greatly simplify the programming
of the multicast filter. This solves the last reported "device timeout"
problem with this driver.
to the EPIC/100 driver's (adjusting for the fact that Intel Ethernet chips
are from Pluto):
* Don't allocate receive buffers until the interface is actually brought
up, and release all of them if the interface is taken down.
* Add a knob (defaults to off) which will copy an incoming packet to
a single header mbuf if it is small enough to fit in one, rather than
burning an entire cluster on it. Note that this change will be mostly
moot if/when sbcompress() is changed to handle compressing clusters.
Simplify some of the receive list logic:
* Rather than using a homegrown queue and additional software RX descriptors,
use an ifqueue to queue receive buffers, and M_{GET,SET}CTX() to hook DMA
maps and receive buffers together.
Clean up a bit:
* Macroize a bunch of things to make the code a bit easier to follow.
