Module Name:	src
Committed By:	thorpej
Date:		Tue Oct  5 20:14:52 UTC 2004

Modified Files:
	src/sys/dev/pci: if_wm.c

Log Message:
Work around another problem (that causes horrible performance) on the 82547:
- Change the Tx:Rx on-chip RAM allocation ratio based on MTU:
  => 82547: > 8192 18K:22K, else 10K:30K
  => others: > 8192 24K:40K, else 16K:48K
  Values derived from Linux driver.
- On the 82547, keep track of how much of the Tx FIFO has been used.
  When in half-duplex mode, don't let packets wrap around the FIFO ring
  buffer, because that causes the chip to croak.  Detect this, stall the
  Tx queue, use a timer to wait for the packets to drain from the Tx FIFO,
  reset the internal FIFO pointers, and restart the Tx queue.  Basic
  algorithm (and some magic numbers) derived from FreeBSD and Linux drivers.


To generate a diff of this commit:
cvs rdiff -r1.77 -r1.78 src/sys/dev/pci/if_wm.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.