[alsa-devel] Wandboard Quad - SPDIF issue, no sound

[Michael Howard]

On 24/06/2014 06:33, Sinan Akman wrote:
>
>   Hi Micheal
>
> On 06/23/2014 02:07 PM, Michael Howard wrote:
>> Hello All,
>>
>> I'm resending this email as orignally I wasn't subcribed and I've been
>> told the message hasn't made it through.
>>
>> I was pointed here from the Wandboard Google Groups forum. If I'm in the
>> wrong place please accept my appologies.
>>
>> With known good cabling and receiver I'm not getting sound from the
>> Wandboard Quad's S/PDIF output.
>
>   How are you testing your spdif output exactly ?

Until now, simply from a usage point of view with alsa. That is to say 
aplay, the same as with the cubietruck.
>
>> I have built various kernels from
>> mainline, the last two sources I tried are 3.15.1 and 3.16-rc2.
>>
>> With sound built as modules I get nothing on any outputs, errors from
>> dmesg are;
>>
>> dmesg | grep snd
>> 5.206990] imx-spdif sound-spdif.13: snd_soc_register_card failed: -517
>> [ 5.241976] imx-spdif sound-spdif.13: snd_soc_register_card failed: -517
>> [ 5.258174] imx-spdif sound-spdif.13: snd-soc-dummy-dai <->
>> 2004000.spdif mapping ok
>> [ 5.281704] imx-sgtl5000 sound.12: snd_soc_register_card failed (-517)
>>
>> With sound built in I get sound on the 'line out' output and from dmesg;
>>
>> dmesg | grep snd
>> imx-spdif sound-spdif: snd-soc-dummy-dai <-> 2004000.spdif mapping ok
>>
>> In both cases I get (or similar);
>>
>> dmesg | grep firm
>> imx-sdma 20ec000.sdma: Direct firmware load failed with error -2
>> imx-sdma 20ec000.sdma: loaded firmware 1.1
>>
>> Not sure if the firmware message above is a problem or not.
>
>   No, it should work without loading external firmware to ram.
>
I thought so with current mainline.
>>
>> aplay output;
>>
>> aplay -l
>> **** List of PLAYBACK Hardware Devices ****
>> card 0: imx6wandboardsg [imx6-wandboard-sgtl5000], device 0: HiFi
>> sgtl5000-0 []
>>    Subdevices: 1/1
>>    Subdevice #0: subdevice #0
>> card 1: imxspdif [imx-spdif], device 0: S/PDIF PCM 
>> snd-soc-dummy-dai-0 []
>>    Subdevices: 1/1
>>    Subdevice #0: subdevice #0
>>
>> aplay -L
>> null
>>      Discard all samples (playback) or generate zero samples (capture)
>> pulse
>>      PulseAudio Sound Server
>> sysdefault:CARD=imx6wandboardsg
>>      imx6-wandboard-sgtl5000,
>>      Default Audio Device
>> sysdefault:CARD=imxspdif
>>      imx-spdif,
>>      Default Audio Device
>>
>> aplay -vv ImABeliever.wav
>> Playing WAVE 'ImABeliever.wav' : Signed 16 bit Little Endian, Rate 44100
>> Hz, Stereo
>> Hardware PCM card 1 'imx-spdif' device 0 subdevice 0
>> Its setup is:
>>    stream       : PLAYBACK
>>    access       : RW_INTERLEAVED
>>    format       : S16_LE
>>    subformat    : STD
>>    channels     : 2
>>    rate         : 44100
>>    exact rate   : 44100 (44100/1)
>>    msbits       : 16
>>    buffer_size  : 16384
>>    period_size  : 4096
>>    period_time  : 92879
>>    tstamp_mode  : NONE
>>    period_step  : 1
>>    avail_min    : 4096
>>    period_event : 0
>>    start_threshold  : 16384
>>    stop_threshold   : 16384
>>    silence_threshold: 0
>>    silence_size : 0
>>    boundary     : 1073741824
>>    appl_ptr     : 0
>>    hw_ptr       : 0
>> #################           +                      | 55%
>>
>> but no sound form SPDIF.
>>
>> If this is right place for this and if I can be of any help debuuging or
>> you need more info I'm more than happy to help in any way I can.
>>
>> Since I sent the original message Ive realised that data is being sent
>> to and received at the SPDIF output of the wandboard quad it can't seem
>> to handle it.
>
>   This is somewhat unclear. If you confirm that the data is being
> set to spdif port correctly, what do you mean by "it can't seem to
> handle it" ?
>
I probably should have phrased this as 'data arrives at the SPDID output 
but is not understood at the receiver'? The cubietruck manages this task 
though with the same data, same commands so the two SPDIF outputs are 
doing somethin differently? Or am I being to simplistic? :)
>
>> If I connect a DAC to the SPDIF output and then connect
>> the DAC to my recievers aux input I hear the sound in all it's glory.
>
>   If you have your spdif output connected to dac and that works fine
> then I would say your spdif is just fine. There might be something
> specific with your receiver.
>
>>
>> The same receiver and cabling works with a cubietruck and the sunxi 
>> kernel.
>
>   I would suggest you hook up a scope to your spdif output for both
> wandboard and cubietruck and compare the signals. Perhaps the voltage
> levels are too low for your receiver. You might want to try another
> receiver, but I would check the scope outputs first.
Ok, I'll 'hook up  a scope' and get back to the list but I am a complete 
amateur :)
I have tried a second receiver and the results are the same, as in, the 
wandboard fails, the cubietruck works. I fear that this a design issue 
and I'm wasting your time.

Cheers
Mike.

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