ad1988 spdif crackling (includes patch)

ad1988 spdif crackling (includes patch)

[Robin Kreis]

Hi!

For nearly three years, a bug has been known to cripple SPDIF output on
certain hardware.  It might work fine for a while, but will randomly
break, showing two symptoms:  PCM audio is distorted (similar to
clipping) while compressed audio (AC3 or DTS) will not work at all.
Muting an unmuting the master channel may temporarily fix it.

This affects at least all Asus P5B and P6B mainboards.

The solution is a simple one-liner, and has been known for a year:  
http://fjerhammer.dk/ad1988_spdif_crackling.patch (credits go to Javeed
Shaikh for the patch and fjerhammer for hosting it).  I can verify that
it fixes all issues on my setup.  Please apply it.

See also:
https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/359361

Greetings,
Robin Kreis

Re: ad1988 spdif crackling (includes patch)

[Raymond Yau]

>
> Hi!
>
> For nearly three years, a bug has been known to cripple SPDIF output on
> certain hardware.  It might work fine for a while, but will randomly
> break, showing two symptoms:  PCM audio is distorted (similar to
> clipping) while compressed audio (AC3 or DTS) will not work at all.

can you post the output of alsa-info.sh ?

do turn off this switch help ?

Simple mixer control 'IEC958 Default PCM',0
  Capabilities: pswitch pswitch-joined penum
  Playback channels: Mono
  Mono: Playback [on]

are your application using  hw:0,0 , iec958:0  or hw:0,1 for digital output
?

http://support.asus.com/Search/KDetail.aspx?SLanguage=en&no=BFFD12B9-1255-7974-9DA6-F5F7C47689DC&t=2

the supported rates of device 0 is restricted to the supported rates of
node 0x02 when the above switch is ON and the driver don't protect the
switch when the application is playing

Default PCM:
    rates [0x7ff]: 8000 11025 16000 22050 32000 44100 48000 88200 96000
176400 192000
    bits [0xe]: 16 20 24
    formats [0x1]: PCM
Default Amp-In caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
Default Amp-Out caps: ofs=0x27, nsteps=0x27, stepsize=0x05, mute=0
Node 0x02 [Audio Output] wcaps 0x30311: Stereo Digital
  PCM:
    rates [0x7e0]: 44100 48000 88200 96000 176400 192000
    bits [0xe]: 16 20 24
    formats [0x5]: PCM AC3
  Connection: 1
     0x1d
Node 0x03 [Audio Output] wcaps 0x405: Stereo Amp-Out
  Amp-Out caps: ofs=0x27, nsteps=0x27, stepsize=0x05, mute=0
  Amp-Out vals:  [0x27 0x27]
  Power: 0x0

it seem that those paths from ADC to SPDIF does not exist

Simple mixer control 'IEC958 Playback Source',0
  Capabilities: enum
  Items: 'PCM' 'ADC1' 'ADC2' 'ADC3'
  Item0: 'PCM'

http://support.asus.com/Search/KDetail.aspx?SLanguage=en&no=9b4f722c-dd89-90ee-e40c-feff297d69dd&t=2

AD1988 does not support Mic to SPDIF.

> Muting an unmuting the master channel may temporarily fix it.
>
> This affects at least all Asus P5B and P6B mainboards.

http://support.asus.com/Search/KDetail.aspx?SLanguage=en&no=02A7151F-D599-AA35-9B57-976ED19FACE4&t=2

http://git.kernel.org/?p=linux/kernel/git/tiwai/hda-emu.git;a=tree;f=codecs;hb=HEAD

http://www.asus.com/Motherboards/Intel_Socket_775/P5Q_Deluxe/#specifications

0n those P5Q deluxe (ad1989b), there are coaxial and spdif out ports but no
hdmi

ADI® AD2000B 8-channel High Definition Audio CODEC
- Coaxial/Optical S/PDIF out ports at back I/O

>
> The solution is a simple one-liner, and has been known for a year:
> http://fjerhammer.dk/ad1988_spdif_crackling.patch (credits go to Javeed
> Shaikh for the patch and fjerhammer for hosting it).  I can verify that
> it fixes all issues on my setup.  Please apply it.
>
> See also:
> https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/359361

do the bug affect all ad198x since the two reporters who posted the codec
info are using ad1984 ?
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Re: ad1988 spdif crackling (includes patch)

[Takashi Iwai]

At Tue, 30 Oct 2012 13:02:27 +0100,
Robin Kreis wrote:
> 
> Hi!
> 
> For nearly three years, a bug has been known to cripple SPDIF output on
> certain hardware.  It might work fine for a while, but will randomly
> break, showing two symptoms:  PCM audio is distorted (similar to
> clipping) while compressed audio (AC3 or DTS) will not work at all.
> Muting an unmuting the master channel may temporarily fix it.
> 
> This affects at least all Asus P5B and P6B mainboards.
> 
> The solution is a simple one-liner, and has been known for a year:  
> http://fjerhammer.dk/ad1988_spdif_crackling.patch (credits go to Javeed
> Shaikh for the patch and fjerhammer for hosting it).  I can verify that
> it fixes all issues on my setup.  Please apply it.
> 
> See also:
> https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/359361

Now applied the fix.  Thanks for reporting.


Takashi