On Tue, Feb 11, 2003 at 12:35:01PM -0500, Stephan Uphoff wrote:

 > The i82257 driver ignores this problem and just illegally calls 
 > bus_dmamap_sync with
 > BUS_DMASYNC_POSTXXXX flags with full knowledge that the DMA might not have 
 > completed.
 > ( When it finds out that the DMA did not complete it just calls bus_dmamap_sync
 > again with BUS_DMASYNC_PREXXXX op flags)

This is not illegal... this is an acceptable/intended use of the interface
(I should know -- I designed the interface and wrote the code that you're
citing :-)

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