> And how does that manufacturer tell you to use it? Get the clock started and configure. The loss of the WS signal is not intended and is a failure. A xrun results in configuration loss. > Anyway, it might be possible to write an external filter plugin: > https://www.alsa-project.org/alsa-doc/alsa-lib/pcm_external_plugins.html I am doing that right now. Right now. It compiles but does not start: $ cat ~/.asoundrc pcm_hw_internal { type hw card 0 device 0 } pcm.myplugin { type myplugin slave { pcm pcm_hw_internal } } $ arecord -D myplugin /dev/zero ALSA lib dlmisc.c:142:(snd_dlsym_verify) unable to verify version for symbol _snd_pcm_myplugin_open ALSA lib dlmisc.c:263:(snd1_dlobj_cache_get) symbol _snd_pcm_myplugin_open is not defined inside /usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_myplugin.so arecord: main:722: audio open error: No such device or address This looks like a compile problem, but I don't what exactly. It is compiled like this: $ gcc -I/usr/include/alsa -Wall -g -lasound -fPIC -DPIC -shared -o build/libasound_module_pcm_myplugin.so alsa-plugin.c FYI: I am just testing this on my local machine (ubuntu 16.04) with pulseaudio killed (and autospawn=no). > Does the kernel driver start the I²S clocks in hw_params() or in trigger()? I cannot tell because I am not versed enough in device/ALSA/SOC drivers but I made a step by step device initialization via alsa-lib and the clock really starts only the device is written or read. The SOC manufacturer supplies the ALSA device drivers that utilizes the I2S/PCM interface to talk to the audio controller which I need to configure. Regards, Thomas Frank ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
