[alsa-devel] Assert in pcm_params.c

[Alan Horstmann]

On Saturday 18 April 2015 09:08, I wrote:
> 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?

Regards

Alan