SiS devices seem unable to reset dma block index to zero, causing dma to start at the wrong place. Workaround this limitation by starting at the current offset.
SiS devices seem unable to reset dma block index to zero, causing
dma to start at the wrong place. Workaround this limitation by
starting at the current offset.

From Christopher Zimmermann <madroach at zakweb.de>
Thanks a lot!

ok jakemsr

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars