On Fri, Apr 20, 2001 at 04:18:48AM +0300, Matt Thomas wrote:

 > Module Name:	syssrc
 > Committed By:	matt
 > Date:		Fri Apr 20 01:18:47 UTC 2001
 > 
 > Modified Files:
 > 	syssrc/sys/arch/macppc/dev: if_gm.c
 > 
 > Log Message:
 > After finishing with the received descriptor, make sure to "eieio" to make
 > sure the OWN gets back to the gmac in the proper order.  This reduces (and
 > maybe even fixes) the gm0 out-of-order problem.

This should be handled in the bus_dma functions.  Look at the description
of bus_dmamap_sync() in bus_dma(9), and also note that the Alpha port does
an "mb" (memory barrier) instruction in bus_dmamap_sync().

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>