O PulseAudio não consegue abrir o dispositivo PCM

Question

Eu tenho uma placa baseada em IMX6Q e quero jogar com o PulseAudio. Minha placa tem três dispositivos de som:

# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: tlv320aic3xaudi [tlv320aic3x-audio], device 0: HiFi tlv320aic3x-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: tlv320aic32x4au [tlv320aic32x4-audio], device 0: HiFi tlv320aic32x4-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: imxhdmisoc [imx-hdmi-soc], device 0: i.MX HDMI Audio Tx hdmi-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0

O dispositivo que eu gostaria de usar é hw:1,0 :

aplay -D plughw:1,0 /usr/share/sounds/2.wav

Isso funcionou bem.

Mas, no início, o PulseAudio não detecta dispositivos PCM. Quando tento configurar manualmente o PulseAudio via

# pactl load-module module-alsa-sink device="hw:1,0"

Eu recebo a resposta:

Failure: Module initialization failed

e começando manualmente com

# pulseaudio --system -vvvv --log-meta

retorna:

I: [pulseaudio][pulsecore/client.c:80 pa_client_new()] Created 1 "Native client (UNIX socket client)"
I: [pulseaudio][pulsecore/protocol-native.c:5012 pa_native_protocol_connect()] Client authenticated anonymously.
D: [pulseaudio][pulsecore/protocol-dbus.c:799 pa_dbus_protocol_add_interface()] Interface org.PulseAudio.Core1.Client added for object /org/pulseaudio/core1/client1
D: [pulseaudio][pulsecore/protocol-native.c:2601 command_auth()] Protocol version: remote 29, local 29
D: [pulseaudio][pulsecore/protocol-native.c:2664 command_auth()] SHM possible: no
D: [pulseaudio][pulsecore/protocol-native.c:2682 command_auth()] Negotiated SHM: no
D: [pulseaudio][modules/alsa/alsa-util.c:673 pa_alsa_open_by_device_string()] Trying hw:1,0 with SND_PCM_NO_AUTO_FORMAT ...
I: [pulseaudio][(alsa-lib)pcm_hw.c:1667 _snd_pcm_hw_open()] Invalid value for card
I: [pulseaudio][modules/alsa/alsa-util.c:680 pa_alsa_open_by_device_string()] Error opening PCM device hw:1,0: No such file or directory
E: [pulseaudio][pulsecore/module.c:175 pa_module_load()] Failed to load module "module-alsa-sink" (argument: "device=hw:1,0"): initialization failed.
I: [pulseaudio][pulsecore/client.c:102 pa_client_free()] Freed 1 "pactl"
I: [pulseaudio][pulsecore/protocol-native.c:4903 pstream_die_callback()] Connection died.
D: [pulseaudio][pulsecore/protocol-dbus.c:835 pa_dbus_protocol_remove_interface()] Interface org.PulseAudio.Core1.Client removed from object /org/pulseaudio/core1/client1

Como posso obter o PulseAudio para carregar o dispositivo?