[Bug] 7.0.2.009 No Analog Output s905x - X96 2G16G

Jaaxx · November 27, 2016 at 2:13 AM

Bug: No output from AV jack.

Device: (Tomato?) X96 s905x 2G/16G connected to various amplifiers via both original AV cable and standard 3.5mm to RCA cable.

Affects: 7.0.2.009 and all devel versions up to and including 11/26/16

Notes:
AV out DOES work in original Android firmware
HDMI audio works perfectly (except for pops on connect/disconnect which has been reported elsewhere)
SPDIF (optical) has not been tested yet (waiting on D/A converter)
In LE i2s and spdif are muted by default in alsamixer.
Unmuting or muting i2s causes a popping in any device attached to AV jack via either the included AV cable or a standard 3.5mm audio cable. The same popping also occurs anytime the soundcard wakes or sleeps and can be heard through the HDMI audio stream as well.
Increasing "DAC Extra Digital Gain" above 0db causes a very faint hissing to be heard from devices attached to AV jack.

Speculation on my part, but the hissing at very high gains seems to indicate that a signal IS being output via AV. However, it seems that the Kodi audio stream is somehow not being routed properly.

Logs and additional info:

Screenshot from alsamixer before unmuting i2s and spdif:

Full Log Set from clean install (system booted, liveTV stream started (mythPVR)): Logset 11/26

Code

aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: AMLM8AUDIO [AML-M8AUDIO], device 0: I2S.39 T9015-audio-hifi-0
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: AMLM8AUDIO [AML-M8AUDIO], device 1: SPDIF.40 dit-hifi-1
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: AMLM8AUDIO [AML-M8AUDIO], device 2: PCM.41 pcm2bt-pcm-2
  Subdevices: 1/1
  Subdevice #0: subdevice #0

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Code

amixer
Simple mixer control 'Lineout left N switch',0
  Capabilities: enum
  Items: 'None' 'LOLN_SEL_DACL_INV' 'LOLN_SEL_DACL'
  Item0: 'LOLN_SEL_DACL_INV'
Simple mixer control 'Lineout left P switch',0
  Capabilities: enum
  Items: 'None' 'LOLP_SEL_DACL' 'LOLP_SEL_DACL_INV'
  Item0: 'LOLP_SEL_DACL'
Simple mixer control 'Lineout right N switch',0
  Capabilities: enum
  Items: 'None' 'LORN_SEL_DACR_INV' 'LORN_SEL_DACR'
  Item0: 'LORN_SEL_DACR_INV'
Simple mixer control 'Lineout right P switch',0
  Capabilities: enum
  Items: 'None' 'LORP_SEL_DACR' 'LORP_SEL_DACR_INV'
  Item0: 'LORP_SEL_DACR'
Simple mixer control 'Audio i2s mute',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'Audio spdif mute',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'DAC Digital',0
  Capabilities: pvolume
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 255
  Mono:
  Front Left: Playback 251 [98%] [-11.25dB]
  Front Right: Playback 251 [98%] [-11.25dB]
Simple mixer control 'DAC Extra Digital Gain',0
  Capabilities: enum
  Items: '0dB' '6dB' '12dB' '18dB'
  Item0: '0dB'
Simple mixer control 'Ext Spk',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]

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Code

amixer -c 0 contents
numid=8,iface=MIXER,name='Lineout left N switch'
  ; type=ENUMERATED,access=rw------,values=1,items=3
  ; Item #0 'None'
  ; Item #1 'LOLN_SEL_DACL_INV'
  ; Item #2 'LOLN_SEL_DACL'
  : values=1
numid=9,iface=MIXER,name='Lineout left P switch'
  ; type=ENUMERATED,access=rw------,values=1,items=3
  ; Item #0 'None'
  ; Item #1 'LOLP_SEL_DACL'
  ; Item #2 'LOLP_SEL_DACL_INV'
  : values=1
numid=6,iface=MIXER,name='Lineout right N switch'
  ; type=ENUMERATED,access=rw------,values=1,items=3
  ; Item #0 'None'
  ; Item #1 'LORN_SEL_DACR_INV'
  ; Item #2 'LORN_SEL_DACR'
  : values=1
numid=7,iface=MIXER,name='Lineout right P switch'
  ; type=ENUMERATED,access=rw------,values=1,items=3
  ; Item #0 'None'
  ; Item #1 'LORP_SEL_DACR'
  ; Item #2 'LORP_SEL_DACR_INV'
  : values=1
numid=3,iface=MIXER,name='Audio i2s mute'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=4,iface=MIXER,name='Audio spdif mute'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=1,iface=MIXER,name='DAC Digital Playback Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=255,step=0
  : values=251,251
  | dBscale-min=-952.50dB,step=3.75dB,mute=1
numid=2,iface=MIXER,name='DAC Extra Digital Gain'
  ; type=ENUMERATED,access=rw------,values=1,items=4
  ; Item #0 '0dB'
  ; Item #1 '6dB'
  ; Item #2 '12dB'
  ; Item #3 '18dB'
  : values=0
numid=5,iface=MIXER,name='Ext Spk Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=10,iface=PCM,name='Playback Channel Map'
  ; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
amixer: Control hw:0 element read error: Invalid argument

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**kszaq** · November 27, 2016 at 9:57 AM

Thank you for very detailed report! This will be looked into. One thing: can you tell if analog audio works in 7.0.2.008? You can downgrade by "updating" without wiping your user data.

Jaaxx · November 27, 2016 at 5:31 PM

I will try 008 this evening and hopefully I will have an A/D converter to test the optical spdif output tomorrow. It's been driving me nuts not knowing if spdif is working silently all this time.

I have a bit of experience working with sound devices in Linux, I was the realtime kernel guy for PCLinuxOS for a time and had a studio recording based distro RocXshop. Unfortunately this arm based sound system has me a little flummoxed. At this point I would love to tell if this is an issue with driver/alsa config or with device tree.

If it helps HERE is the dtb extracted from the original android firmware.

**kszaq** · November 27, 2016 at 5:43 PM

I don't know much about the sound drivers. You should also note that Amlogic's sound drivers are a bit messy and Kwiboo is working very hard to improve them: sound/soc/aml/m8: work-in-progress by Kwiboo · Pull Request #23 · LibreELEC/linux-amlogic · GitHub

If you can tell that analog audio is working in 7.0.2.008 I would be able to pass that information to Kwiboo to take S905X analog out into consideration.

Jaaxx · November 27, 2016 at 10:20 PM

Got impatient. Analog in 008 is not working

Controls available are very different. Also, muting/unmuting i2s and spdif does not produce the popping sounds like in 009.

Code

amixer
Simple mixer control 'Audio i2s mute',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]
Simple mixer control 'Audio spdif mute',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]
Simple mixer control 'Ext Spk',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]

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Code

aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: AMLM8AUDIO [AML-M8AUDIO], device 0: I2S.39 dummy-0
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: AMLM8AUDIO [AML-M8AUDIO], device 1: SPDIF.40 dit-hifi-1
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: AMLM8AUDIO [AML-M8AUDIO], device 2: PCM.41 pcm2bt-pcm-2
  Subdevices: 1/1
  Subdevice #0: subdevice #0

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Jaaxx · November 29, 2016 at 2:36 AM

SPDIF does work sort of. I get a signal via optical. However the volume is very low unless I enable passthrough.

Also telling is that my attached amp detects Pro Logic mode in normal mode and Dolby Digital in passthrough for some reason.

I believe that in passthrough the channel settings, etc are working correctly. In normal non-passthrough mode, the volume is very low and the center channel is so predominant that it sounds horrible.

I did discover that the analog output DOES have a signal, but it is very, very faint. On a 100W amp with all volumes cranked to max and all volumes in Kodi maxed I can barely make out the audio. I still suspect that we are missing some controls in alsa, etc. There SHOULD be a volume control for both i2s and spdif. As it is now, there is neither and the DAC volume which is available has no effect on any output stream.

namdas · March 13, 2017 at 9:29 PM

Hey Jaax,
Did you get to the root of this in the end? I seem to be experiencing exactly the same symptoms but really need to use analog not digital audio