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SND_HDA(4)             FreeBSD Kernel Interfaces Manual             SND_HDA(4)

     snd_hda - Intel High Definition Audio bridge device driver

     To compile this driver into the kernel, place the following lines in your
     kernel configuration file:

           device sound
           device snd_hda

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


     The High Definition (HD) Audio specification was developed by Intel as
     the logical successor of the old AC'97 specification and has several
     advantages, such as higher bandwidth which allows more channels and more
     detailed formats, support for several logical audio devices, and general
     purpose DMA channels.

     The snd_hda driver is a HDA bus controller driver and HDA codecs audio
     functions bridge driver 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).  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

   Boot-time Configuration
     The following variables are available at boot-time through the
     device.hints(5) file:

           hint.hdac.%d.config      Configures a range of possible options.
                                    Possible values are: ``dmapos'',
                                    ``eapdinv'', ``gpio0'', ``gpio1'',
                                    ``gpio2'', ``gpio3'', ``gpio4'',
                                    ``gpio5'', ``gpio6'', ``gpio7'',
                                    ``gpioflush'', ``ivref'', ``ivref50'',
                                    ``ivref80'', ``ivref100'', ``fixedrate'',
                                    ``forcestereo'', ``ovref'', ``ovref50'',
                                    ``ovref80'', ``ovref100'', ``senseinv'',
                                    ``softpcmvol'', and ``vref''.  An option
                                    prefixed with ``no'', such as
                                    ``nofixedrate'', will do the opposite and
                                    takes precedence.  Options can be
                                    separated by whitespace and commas.

                                    ``GPIOs'' are a codec's General Purpose
                                    I/O pins which system integrators
                                    sometimes use to control external muters,
                                    amplifiers and so on.  If you have no
                                    sound, or sound volume is not adequate,
                                    you may have to experiment a bit with the
                                    GPIO setup to find the optimal setup for
                                    your system.

                                    The ``ivrefX'' and ``ovrefX'' options
                                    control the voltage used to power external

           hint.hdac.%d.msi         Controls MSI (Message Signaled Interrupts)

                                    Overrides codec pin configuration set by
                                    BIOS.  May be specified as a 32-bit
                                    hexadecimal value with a leading ``0x'',
                                    or as a set of space-separated
                                    ``option=value'' pairs.

     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

     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 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.

                        For output assotiations sequence numbers encode
                        speaker 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) -

                        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.

           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.

   Runtime Configuration
     The following sysctl(8) variables are available in addition to those
     available to all sound(4) devices:

           dev.hdac.%d.polling      Enables polling mode.  In this mode the
                                    driver operates by querying the device
                                    state on timer ticks using callout(9)
                                    instead of interrupts.  Polling is
                                    disabled by default.  Do not enable it
                                    unless you are facing weird interrupt
                                    problems or if the device cannot generate
                                    interrupts at all.

                                    Controller/Jack Sense polling interval
                                    (1-1000 ms)

           dev.hdac.%d.pindump      Setting this to a non-zero value dumps the
                                    current pin configuration, main
                                    capabilities and jack sense status to
                                    console and syslog.

     Taking HP Compaq DX2300 with Realtek ALC888 HDA codec for example.  This
     system has two audio connectors on a front side, three audio connectors
     on a rear side and one internal speaker.  According to verbose driver
     output and the codec datasheet, this codec has five stereo DACs and two
     stereo ADCs, all of them are routable to any codec pin (external
     connector).  All codec pins are reversible (could be configured either as
     input or output).

     So high codec uniformity and flexibility allow driver to configure it in
     many different ways, depending on requested pins usage described by pins
     configuration.  The driver reports such default pin configuration when
     verbose messages enabled:

     hdac0: nid 20 0x01014020 as  2 seq  0   Line-out  Jack jack 1 loc  1 color   Green misc 0
     hdac0: nid 21 0x99130110 as  1 seq  0    Speaker Fixed jack 3 loc 25 color Unknown misc 1
     hdac0: nid 22 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 23 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 24 0x01a19830 as  3 seq  0        Mic  Jack jack 1 loc  1 color    Pink misc 8
     hdac0: nid 25 0x02a1983f as  3 seq 15        Mic  Jack jack 1 loc  2 color    Pink misc 8
     hdac0: nid 26 0x01813031 as  3 seq  1    Line-in  Jack jack 1 loc  1 color    Blue misc 0
     hdac0: nid 27 0x0221401f as  1 seq 15 Headphones  Jack jack 1 loc  2 color   Green misc 0
     hdac0: nid 28 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 30 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1
     hdac0: nid 31 0x411111f0 as 15 seq  0    Speaker  None jack 1 loc  1 color   Black misc 1

     Here we can see, that the nodes with ID (nid) 25 and 27 are front panel
     connectors (Jack, loc 2), nids 20, 24 and 26 are rear panel connectors
     (Jack, loc 1) and nid 21 is a built-in speaker (Fixed, loc 25).  Pins
     with nids 22, 23, 28, 30 and 31 will be disabled by driver due to "None"
     connectivity. So the pin count and description matches to connectors that
     we have.

     Using association (as) and sequence (seq) fields values pins are grouped
     into 3 associations:

     hdac0: Association 0 (1) out:
     hdac0:   Pin nid=21 seq=0
     hdac0:   Pin nid=27 seq=15
     hdac0: Association 1 (2) out:
     hdac0:   Pin nid=20 seq=0
     hdac0: Association 2 (3) in:
     hdac0:   Pin nid=24 seq=0
     hdac0:   Pin nid=26 seq=1
     hdac0:   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:

   Example 1
     Setting the device.hints(5) options


     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

   Example 2
     Setting the device.hints(5) options

     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.

   Example 3
     Setting the device.hints(5) options

     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).

   Example 4
     Setting the device.hints(5) options

     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.

     Depending on codec configuration, these controls and signal sources could
     be reported to sound(4):

           vol          overall output level (volume)

           rec          overall recording level

           igain        input-to-output monitoring loopback level

           ogain        external amplifier control

           pcm          PCM playback

           mix          input mix

           mic          first external or second internal microphone input

           monitor      first internal or second external microphone input

           line, line1, line2, line3
                        analog (line) inputs

           dig1, dig2, dig3
                        digital (S/PDIF, HDMI or DisplayPort) inputs

           cd           CD input

           speaker      PC speaker input

           phin, phout, radio. video
                        other random inputs

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

     The snd_hda driver supports many Intel HDA compatible audio chipsets
     including the following:

     +o   ATI SB450
     +o   ATI SB600
     +o   Intel 631x/632xESB
     +o   Intel 82801F (ICH6)
     +o   Intel 82801G (ICH7)
     +o   Intel 82801H (ICH8)
     +o   Intel 82801I (ICH9)
     +o   Intel 82801J (ICH10)
     +o   Intel US15W (SCH)
     +o   nVidia MCP51
     +o   nVidia MCP55
     +o   nVidia MCP61A
     +o   nVidia MCP61B
     +o   nVidia MCP63
     +o   nVidia MCP65A
     +o   nVidia MCP65B
     +o   nVidia MCP67A
     +o   nVidia MCP67B
     +o   nVidia MCP68
     +o   nVidia MCP69
     +o   nVidia MCP73
     +o   nVidia MCP78
     +o   nVidia MCP79
     +o   nVidia MCP89
     +o   SiS 966
     +o   VIA VT8251/8237A

     The following and many other codecs have been verified to work:

     +o   Analog Devices AD1981HD
     +o   Analog Devices AD1983
     +o   Analog Devices AD1984
     +o   Analog Devices AD1986A
     +o   Analog Devices AD1988
     +o   Analog Devices AD1988B
     +o   CMedia CMI9880
     +o   Conexant CX20549 (Venice)
     +o   Conexant CX20551 (Waikiki)
     +o   Conexant CX20561 (Hermosa)
     +o   Realtek ALC260
     +o   Realtek ALC262
     +o   Realtek ALC268
     +o   Realtek ALC660
     +o   Realtek ALC861
     +o   Realtek ALC861VD
     +o   Realtek ALC880
     +o   Realtek ALC882
     +o   Realtek ALC883
     +o   Realtek ALC885
     +o   Realtek ALC888
     +o   Realtek ALC889
     +o   Sigmatel STAC9205
     +o   Sigmatel STAC9220
     +o   Sigmatel STAC9220D / 9223D
     +o   Sigmatel STAC9221
     +o   Sigmatel STAC9221D
     +o   Sigmatel STAC9227D
     +o   Sigmatel STAC9227X
     +o   Sigmatel STAC9228D
     +o   Sigmatel STAC9228X
     +o   Sigmatel STAC9229D
     +o   Sigmatel STAC9229X
     +o   Sigmatel STAC9230D
     +o   Sigmatel STAC9230X
     +o   Sigmatel STAC9271D
     +o   Sigmatel STAC9872AK
     +o   VIA VT1708
     +o   VIA VT1708B
     +o   VIA VT1709

     sound(4), snd_ich(4), device.hints(5), loader.conf(5), sysctl(8)

     The snd_hda device driver first appeared in FreeBSD 6.3.

     The snd_hda driver was written by Stephane E. Potvin
     <>, Ariff Abdullah <> and Alexander
     Motin <>.  This manual page was written by Joel Dahl
     <>, Alexander Motin <> and Giorgos
     Keramidas <>.

     A few Hardware/OEM vendors tend to screw up BIOS settings, thus rendering
     the snd_hda driver useless.  This usually results in a state where the
     snd_hda driver seems to attach and work, but no sound is played.  Some
     cases can be solved by tuning loader.conf variables.  Before trying to
     fix problem that way, make sure that there really is a problem and that
     the PCM audio device in use really corresponds to the expected audio

     Some vendors use non-standardized General Purpose I/O (GPIO) pins of the
     codec to control external amplifiers.  In some cases setting a
     combination of GPIO bits may be needed to make sound work on a specific

     HDMI and DisplayPort audio may also require support from video driver.

FreeBSD 11.0-PRERELEASE        January 22, 2010        FreeBSD 11.0-PRERELEASE


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