Module Name:	src
Committed By:	thorpej
Date:		Fri Feb 12 05:55:28 UTC 1999

Modified Files:
	src/sys/dev/ic: smc83c170.c smc83c170var.h
Log Message:
Cleanup of the EPIC/100 driver I did while hacking on the Rhine driver:
* Macroize hardware and software descriptor access (much easier to read).
* Simplify and optimize the transmit loop a bit, and use IFF_OACTIVE as
appropriate.
* Fix a potential race condition in the transmit loop.  This change has
made the driver significantly more stable (almost completely eliminated
the "device timeout" errors that have plagued this driver).
* Implement transmit interrupt pacing.
* Add missing bus_dmamap_sync() calls (on transmit and receive descriptors
and fraglists).  (Draining the write buffer when accessing these structures
may have also contributed to the increased stability of this driver on
the Alpha.)