AC97(4) BSD Kernel Interfaces Manual AC97(4)NAMEac97 — generic AC97 codec driver
DESCRIPTION
AC97 codecs contain the analog-to-digital (A/D), digital-to-analog (D/A),
and mixing circuitry of many modern sound cards. AC97 codecs, for the
most part, do not talk to host busses like the PCI bus directly.
Instead, they communicate through an interface chip, called the host con‐
troller. The Ensoniq AudioPCI 97 (see eap(4)) is an example of such a
host controller.
Unlike many drivers, the ac97 driver does not appear in the configuration
file. Instead, the driver is automatically attached by the drivers that
require it.
SEE ALSOauacer(4), auich(4), auixp(4), autri(4), auvia(4), clcs(4), clct(4),
eap(4), emuxki(4), esa(4), esm(4), fms(4), neo(4), yds(4)BUGS
The ac97 driver does not keep track of the current user settings and
instead relies on the hardware to do this.
The ac97 driver could do more to detect mixer channels that don't work
and cull them from the list.
BSD October 7, 1999 BSD