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
have
yet to ascertain full details, but it is trying successive sample
rates
to see which are valid.
Further info: this occurs with an Intel motherboard/soundcard,
attempting
to open and config the stream at 44100 using front, surround or hdmi
pcm,
having previously opened and tried at a lower, not-supported samplerate, and closed. AFAIK other pcms work OK.
The assert is hit with all current Debian and Ubuntu distros, for
example
Debian 8 (jessie) 32 bit: kernel 3.16.0-4-686-pae (Alsa 1.0.28)but is not seen with Fedora 20 or OpenSuse 12.1 (do they have asserts off?).
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?
I will try to conceive some more tests. How can we debug this further?
A minimal self-contained demo program ('test-format') has been developed
and
is attached, that demonstrates the issue 100% on the reporters machine (HDA-Intel, 6-ch I believe). The output is:
root@Xeon:/home/patest# ./test-format Testing device front Num channels 6 Testing rate: 22050 Result:...Invalid Sample Rate Testing rate: 32000 Result:...Invalid Sample Rate test-format: pcm_params.c:2249: snd1_pcm_hw_params_slave: Assertion `err = 0' failed. Testing rate: 44100 Aborted
Alsa-info is at:
http://www.alsa-project.org/db/?f=19dfeee29f73007e61a00a8fabe3c958f7cb8e87
This apparently happens with or without Pulseaudio running, with just the single 44100 rate, and also with surround devices. Also, on all current Debian and Ubuntu - we have focused on Jessie.
I do not have a machine with similar hardware, so cannot duplicate the results.
Cannot reproduce the assert
But the only plugin associated with front device is softvol
Do the assert still occur with hw device ?(without softvol plugin)
You need to provide debug output by define RULES_DEBUG in pcm_params.c
What value do the distribution use for hda prealloc max size ?
snd_pcm_hw_params() may fail with invalid argument even when pa_isFormataupported return true