Manual Pages  — SND_HDA

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

snd_hda_load="YES"

The snd_hda driver includes HDA bus controller driver (hdac), HDA codec driver (hdacc) and HDA codecs audio functions bridge driver (hdaa) that allows the generic audio driver, sound(4), to be used with this hardware. Only audio functions are supported by snd_hda. Modem and other possible functions are not implemented.

The snd_hda driver supports hardware that conforms with revision 1.0 of the Intel High Definition Audio specification and tries to behave much like the Microsoft Universal Audio Architecture (UAA) draft (revision 0.7b) for handling audio devices.

According to HDA and UAA specifications, depending on the number of HDA buses and codecs present in system, their audio capabilities and BIOS provided configuration, the snd_hda driver often provides several PCM audio devices. For example, one device for main rear 7.1 output and inputs, one device for independent headset connectors at front and one device for SPDIF or HDMI audio input/output. The assignment of audio inputs and outputs may be tuned with device.hints(5) or sysctl(8). The driver's verbose boot messages provide a lot of information about the operation of the driver and present audio setup.

The default audio device may be tuned by setting the hw.snd.default_unit sysctl, as described in sound(4), or explicitly specified in application settings.

Pin configuration is the UAA driver's main source of information about codec usage. This information is usually provided by the codec manufacturer and tuned by system integrators for specific system requirements. The snd_hda driver allows users to override it to fix integrator mistakes or to use the available codec in alternative ways (for example to get stereo output and 2 inputs instead of a single 5.1 output).

The following options are supported:

as
	Association number. Associations are used to group individual pins to form a complex multi-pin device. For example, to group 4 connectors for 7.1 input/output, or to treat several input connectors as sources for the same input device. Association numbers can be specified as numeric values from 0 to 15. A value of 0 means disabled pin. A value of 15 is a set of independent unassociated pins. Each association includes only pins of the same direction (in/out) and is detected atomically (all pins or none). A separate PCM audio device is created for every pair of input and output associations.
seq
	Sequence number. A unique, per-association number used to order pins inside the particular association. Sequence numbers can be specified as numeric values from 0 to 15. The sequence number 15 has a special meaning for output associations. Output pins with this number and device type "Headphones" will duplicate (with automatic mute if jack detection is supported) the first pin in that association. The sequence numbers 14 and 15 has a special meaning for input associations. Their presence in association defines it as multiplexed or mixed respectively. If none of them are present and there are more than one pin in association, the association will provide multichannel input. For multichannel input/output associations sequence numbers encode channel pairs positions: 0 - Front, 1 - Center/LFE, 2 - Back, 3 - Front Wide Center, 4 - Side. Standard combinations are: (0) - Stereo; (0, 2), (0, 4) - Quadro; (0, 1, 2), (0, 1, 4) - 5.1; (0, 1, 2, 4) - 7.1.
device
	Device type. Can be specified as a number from 0 to 15 or as a name: "Line-out", "Speaker", "Headphones," "CD", "SPDIF-out", "Digital-out", "Modem-line", "Modem-handset", "Line-in", "AUX", "Mic", "Telephony", "SPDIF-in", "Digital-in", "Res.E", or "Other". The device type also describes the pin direction (in/out). For example, "CD" always means an input pin, while "Headphones" always means an output.
conn
	Connection type. Can be specified as a number from 0 to 3. The connection type can also be specified as one of the special names "Jack", "None", "Fixed", or "Both". Pins with a connection type of "None" are disabled.
ctype
	Connector physical type. Can be specified as a number from 0 to 15. This is a reference only value. It is ignored by the snd_hda driver.
color
	Connector color. Can be specified as a number from 0 to 15 or as one of the names "Unknown", "Black", "Grey", "Blue", "Green", "Red", "Orange", "Yellow", "Purple", "Pink", "Res.A", "Res.B", "Res.C", "Res.D", "White", or "Other". This is a reference only value. It is ignored by the snd_hda driver.
loc
	Connector physical location. Can be specified as a number from 0 to 63. This is a reference only value. It is ignored by the snd_hda driver.
misc
	Misc bits. Can be specified as a number from 0 to 15. Bit 0 has a special meaning. When set it means that jack detection is not implemented in hardware.

hdaa0: nid   0x    as seq device       conn  jack    loc        color   misc
hdaa0: 20 01014020 2  0  Line-out      Jack  1/8     Rear       Green   0
hdaa0: 21 99130110 1  0  Speaker       Fixed ATAPI   Onboard    Unknown 1
hdaa0: 22 411111f0 15 0  Speaker       None  1/8     Rear       Black   1 DISA
hdaa0: 23 411111f0 15 0  Speaker       None  1/8     Rear       Black   1 DISA
hdaa0: 24 01a19830 3  0  Mic           Jack  1/8     Rear       Pink    8
hdaa0: 25 02a1983f 3  15 Mic           Jack  1/8     Front      Pink    8
hdaa0: 26 01813031 3  1  Line-in       Jack  1/8     Rear       Blue    0
hdaa0: 27 0221401f 1  15 Headphones    Jack  1/8     Front      Green   0
hdaa0: 28 411111f0 15 0  Speaker       None  1/8     Rear       Black   1 DISA
hdaa0: 30 411111f0 15 0  Speaker       None  1/8     Rear       Black   1 DISA
hdaa0: 31 411111f0 15 0  Speaker       None  1/8     Rear       Black   1 DISA

hdaa0: Association 0 (1) out:
hdaa0:   Pin nid=21 seq=0
hdaa0:   Pin nid=27 seq=15
hdaa0: Association 1 (2) out:
hdaa0:   Pin nid=20 seq=0
hdaa0: Association 2 (3) in:
hdaa0:   Pin nid=24 seq=0
hdaa0:   Pin nid=26 seq=1
hdaa0:   Pin nid=25 seq=15

Each pcm(4) device uses two associations: one for playback and one for recording. Associations processed and assigned to pcm(4) devices in increasing numerical order. In this case association #0 (1) will become pcm0 device playback, using the internal speakers and Headphones jack with speaker automute on the headphones jack connection. Association #1 (2) will become pcm1 playback, using the Line-out jack. Association #2 (3) will become pcm0 recording, using the external microphones and the Line-in jack.

The snd_hda driver provides extensive verbose messages to diagnose its operation logic and describe its current codec configuration.

Using device.hints(5) it is possible to modify the configuration of the existing pins, allowing a broad range of different audio setups. Here are a few examples of some setups possible for this particular hardware:

hint.hdac.0.cad0.nid20.config="as=1"
hint.hdac.0.cad0.nid21.config="as=2"

will swap line-out and speaker functions. So the pcm0 device will play to the line-out and headphones jacks. Line-out will be muted on the headphones jack connection. Recording on pcm0 will go from two external microphones and line-in jacks. pcm1 playback will go to the internal speaker.

hint.hdac.0.cad0.nid20.config="as=1 seq=15 device=Headphones"
hint.hdac.0.cad0.nid27.config="as=2 seq=0"
hint.hdac.0.cad0.nid25.config="as=4 seq=0"

will split the headphones and one of the microphones to a separate device. The pcm0 device will play to the internal speaker and to the line-out jack, with speaker automute on the line-out jack connection. Recording on pcm0 will use input from one external microphone and the line-in jacks. The pcm1 device will be completely dedicated to a headset (headphones and mic) connected to the front connectors.

hint.hdac.0.cad0.nid20.config="as=1 seq=0"
hint.hdac.0.cad0.nid26.config="as=2 seq=0"
hint.hdac.0.cad0.nid27.config="as=3 seq=0"
hint.hdac.0.cad0.nid25.config="as=4 seq=0"
hint.hdac.0.cad0.nid24.config="as=5 seq=0 device=Line-out"
hint.hdac.0.cad0.nid21.config="as=6 seq=0"

will give 4 independent devices: pcm0 (line-out and line-in), pcm1 (headphones and mic), pcm2 (additional line-out via retasked rear mic jack), and pcm3 (internal speaker).

hint.hdac.0.cad0.nid20.config="as=1 seq=0"
hint.hdac.0.cad0.nid24.config="as=1 seq=1 device=Line-out"
hint.hdac.0.cad0.nid26.config="as=1 seq=2 device=Line-out"
hint.hdac.0.cad0.nid21.config="as=2 seq=0"

will give 2 devices: pcm0 for 5.1 playback via 3 rear connectors (line-out and retasked mic and line-in) and headset (headphones and mic) at front connectors. pcm1 for internal speaker playback. On headphones connection rear connectors will be muted.

Controls have different precision. Some could be just an on/off triggers. Most of controls use logarithmic scale.