[alsa-devel] Assert in pcm_params.c

[Raymond Yau]

> > > > > Hi,
> > > > >
> > > > > The following assert is being hit in pcm_params.c:
> > > > >
> > > > > "pcm_params.c:2249: snd1_pcm_hw_params_slave: Assertion `err >=
0'>
> > > > > failed."
> > > > >
> > > > > This is from a developer using Portaudio in his own application; I
> <snip>
> > > > > Does this point to a flaw in the configuration or possibly a bug
in
> > > > > Alsa-lib or can it occur just as a result of misuse of the Alsa
API?
> >
> >
http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m___h_w___params.
> > > >
> > > > Only snd_pcm_hw_params_test_rate() can be call multiple times,
> > > > Verify if a rate is available inside a configuration space for a
PCM.
> > > >
> > > > Those snd_pcm_hw_params_ser_rate*  functions restrict the
configuration
> > > > space to one rate and can be called once only
> > >
> > > The stream is being opened and closed at each attempt.
> >
> > Seem Delta 44 does not support 2,4,6 or 8 channels
>
> This issue is not on Delta44, but an Intel motherboard.  But I would not
> expect to hit an assert in Alsa-lib whatever we do, surely?

> call to Pa_IsFormatSupported(NULL, &outputParameters, samprate ); will
cause a crasch for a certain samprate. The Linrad log file is like this:
TESTING PORTAUDIO DEVICE 10 FOR Rx output

id=10 device=front hostapi=ALSA max_input_chan=0 max_output_chan=6 Testing
0 8000.000000 err=-9997 Invalid sample rate
Testing 1 9600.000000 err=-9997 Invalid sample rate
Testing 2 11025.000000 err=-9997 Invalid sample rate
Testing 3 12000.000000 err=-9997 Invalid sample rate
Testing 4 16000.000000 err=-9997 Invalid sample rate
Testing 5 22050.000000 err=-9997 Invalid sample rate
Testing 6 24000.000000 err=-9997 Invalid sample rate
Testing 7 32000.000000 err=-9997 Invalid sample rate
Testing 8 44100.000000

9600,12000 are not in Table 56. Defined Sample Rates of HDA specification

http://git.kernel.org/cgit/linux/kernel/git/tiwai/hda-emu.git/tree/codecs/ad1988b-asus-p5b-deluxe-wifi?id=HEAD

Most 6 channels audio are at 48000Hz, but some application upmix stereo
44100Hz to 6 channels

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/pci/hda?id=5f1545bc45a33361d6bb2fb44af7c35bcd733b9d

>From the HDA spec it appears that the buffers written to the BDL and
sent to a codec must be 128 byte aligned (section 4.5.1).  The alignment
was not happening especially when playing 6 channels.

Do you mean the driver still have this alignment when playing 6 channel ?
I