- add an additional watchdog for RX overflow
- re-initialise the chip on device timeout
Also alter the interrupt blanking rate to 8 packets, as per OpenSolaris.
documentation, experimentation and a previous patch from John Heasley.
Add improvements to the driver based on the GEM documentation and
from FreeBSD if_gem.c (rev 1.45).
the host share them.
Before breaking out of the loop over descriptors in gem_rint(),
DMA-resynchronize the first Rx descriptor we found that does not
belong to the host. We must avoid a cached descriptor "covering"
a descriptor in RAM, because the cached descriptor may say that
the descriptor still belongs to the NIC, when that is not true,
and the driver will hang.
XXX I believe this driver only works by luck on hosts that both
XXX have a cacheline size greater than the size of a descriptor
XXX (16 bytes) and lack DMA/cache coherency. I need to add some
XXX trickery to make sure that we don't scribble over the NIC's
XXX changes to a descriptor when we flush a cached descriptor to
XXX RAM with bus_dmamap_sync(9).
switch back to MII mode. Keep a sliding window for TX segments and when it
gets > 2/3 full, request a TX interrupt (window gets reset when the h/w TX
queue is empty). Add dv_xname to a few printfs. With the above changes,
the gem driver will now work on Macintoshes, even in GigE mode. On a 733
PowerMac G4 it gets ~355Mb/s TX and ~280Mb/s RX to/from an Alpha XP1000.
XXX mii autoselect is still flakey.
