[oi-dev] pulseaudio issues

[Gary Mills]

On Tue, Apr 02, 2019 at 12:48:03PM +0000, Alexander Pyhalov wrote:

> I've looked through libmatemixer and pulseaudio sources once again
> to recollect exact issue. Now I see, the original issue is the
> following: mod_solaris doesn't have means to set device volume (it
> gets volume via AUDIO_GETINFO sysctl, and this has no any relation
> to real audioctl volume setting, controlled via /dev/mixer.

On illumos, /dev/mixer is simply a symlink to /dev/sndstat .  Here's
what I get by reading that device:

    $ cat /dev/mixer  
    SunOS Audio Framework
    
    Audio Devices:
    0: audiohd#0 onboard1, a (DUPLEX)
    1: audiohd#1 onboard1, a (DUPLEX)
    
    Mixers:
    0: audiohd#0 onboard1, a
            HD codec: ATI R600 HDMI
    1: audiohd#1 onboard1, a
        Unknown HD codec: 0x10ec0887

The hardware mixers are /dev/mixer0 and /dev/mixer1 on my system.

The relevant man page for /dev/mixer is MIXER(7I).  It says, in part:

       The /dev/mixer pseudo-device is provided for two purposes:

           o      The first purpose is for applications that wish to learn
                  about the list of audio devices on the system, so that they
                  can select (or provide for users to select) an appropriate
                  audio device. The /dev/mixer pseudo-device provides
                  interfaces to enumerate all of the audio devices on the
                  system.

           o      The second purpose is for mixer panel type applications
                  which need to control master settings for the audio hardware
                  in the system, such as gain levels, balance, port
                  functionality, and other device features.

and:

       The /dev/sndstat device supports read(2), and can be read to retrieve
       human-readable information about the audio devices on the system.
       Software should not attempt to interpret the contents of this device.

The IOCTLs for /dev/mixer are also described in detail in this man page.

PS: There is a patch to the audiohd driver up for review that enables
HDMI audio devices to work.


-- 
-Gary Mills-		-refurb-		-Winnipeg, Manitoba, Canada-