audiohd(7D) Devices audiohd(7D)NAMEaudiohd - HD audio controller generic codec audio core support
DESCRIPTION
The audiohd driver provides support for the generic codec chips which
are compatible with the Intel High-Definition Audio Controller 1.0
specification.
API
This interface is described in the mixer(7I) and audio(7I) manual
pages.
Driver Versions
Applications that open /dev/audio may use the AUDIO_GETDEV ioctl(2) to
determine which audio device is being used. The audiohd driver returns
the string SUNW,audiohd in the name field of the audio_device struc‐
ture. The version field contains a letter "a" and the config field con‐
tains the string onboard1.
Platform Ver. Out H. Phone Spkr. In Mic. CD
Sun x86/64 workstation w/MCP HD audio a Y Y Y Y Y Y
Key to the above table: Ver. = Version. Out = Line Out. H. Phone = Head
Phone. Spkr = Internal Speaker. In = Line In. Mic. = Microphone. CD =
CD=ROM.
The audiohd device provides support for the internal speaker, head‐
phone, line out, line in, microphone and replicated front panel audio
parts. The play.mod_ports and record.mod_ports fields of the audio_info
structure (see audio(7I)) indicate which ports may be manipulated.
Audio Mixer Mode
This driver supports the mixer mode only. (Compat mode is not sup‐
ported).
Audio Data Formats
The audiohd device supports 16-bit linear encodings in stereo. With
the mixer enabled, a continuous range of sample rates from 5510 to
48000 Hz is supported. With the mixer disabled, only sample rate 48000
Hz is supported.
Sample Granularity
Because the audiohd device follows the Intel HD Audio specification,
buffers of audio data are supplied by streams and the reported input
and output sample counts vary at any given time from the actual sample
count by no more than the size of the buffers the audiohd driver is
transferring. As a rule, programs should not rely on the absolute accu‐
racy of the play.samples and record.samples fields of the audio_info
structure.
Interrupt Rate
The driver determines how often play and record interrupts should take
place. For playing audio, this determines how often and how much audio
is requested from the audio mixer. The impact of interrupts on record‐
ing is minimal. However, if a very small read buffer size is set, the
record interrupt rate should be increased to prevent the buffer from
overflowing. You can use the /kernel/drv/audiohd.conf file to tune the
play and record interrupt rates.
Audio Status Change Notification
As described in the audio(7I) and mixer(7I) man pages, it is possible
to request asynchronous notification of changes in the state of an
audio device.
ERRORSaudiohd errors are described in the audio(7I) man page.
FILES
/dev/audio Symbolic link to the system's primary audio
device. (Not necessarily an audiohd audio
device).
/dev/audioctl Control device for the primary audio
device.
/dev/sound/0 Represents the first audio device on the
system. (Not necessarily an audiohd audio
device).
/dev/sound/0ctl Audio control for /dev/sound/0.
/usr/share/audio/samples Audio sample files.
/kernel/drv/audiohd.conf audiohd driver configuration file.
ATTRIBUTES
See attributes(5) for a descriptions of the following attributes:
┌────────────────────┬──────────────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼──────────────────────────────────────┤
│Architecture │PC-based system │
├────────────────────┼──────────────────────────────────────┤
│Availability │SUNWaudd, SUNWauda │
├────────────────────┼──────────────────────────────────────┤
│Stability level │Evolving │
└────────────────────┴──────────────────────────────────────┘
SEE ALSOmixerctl(1), sdtaudiocontrol(1), ioctl(2), attributes(5), audio(7I),
mixer(7I), streamio(7I)
Intel High-Definition Audio Specification 1.0. - Intel Corporation
ALC880 Specification — Realtek Inc.
http://www.sun.com/io
DIAGNOSTICS
In addition to being logged, the following messages may appear on the
system console:
init_state() play interrupt rate set too low
The play interrupt rate in audiohd.conf is set too low. It has been
reset to the rate specified in the message. Updateaudiohd.conf to a
higher play interrupt rate.
init_state() play interrupt rate set too high
The play interrupt rate set in audio810.conf is set too high. It
has been reset to the rate specified in the message. Updateau‐
diohd.conf to a lower play interrupt rate.
init_state() record interrupt rate set too low
The record interrupt rate inaudiohd.conf is set too low. It has
been reset to the rate specified in the message. Update
audio810.conf to a higher record interrupt rate.
init_state() record interrupt rate set too high
The record interrupt rate in audiohd.conf is set too high. It has
been reset to the rate specified in the message. Updateaudiohd.conf
to a lower record interrupt rate.
SunOS 5.10 25 July 2009 audiohd(7D)
