Replying to a couple of months old thread... On Tue, 2015-06-30 at 18:08 +0300, Tanu Kaskinen wrote: > When module-udev-detect sees a new PCM device, it needs to notify > module-alsa-card about it. module-udev-detect's only interface with > module-alsa-card is pa_module, which is not useful for adding the > notification. I think we should move the bulk of the code in > module-alsa-card.c to a new class: pa_alsa_card. module-udev-detect > would then create pa_alsa_card objects instead of loading > module-alsa-card instances. module-alsa-card would still exist as a > wrapper around pa_alsa_card, but the module would not be used by > module-udev-detect. With pa_alsa_card in place, we can add a > pa_alsa_card_pcm_added() function to its API. > > pa_alsa_card should be defined in src/modules/alsa/alsa-card.[ch] and > included in the libalsa-util.la helper library. In IRC, Arun recently pointed out a problem in replacing module loading with creation of pa_alsa_card objects: users rely on the module interface to unload individual alsa cards, so users won't any more be able to unload cards that have been loaded by module-udev-detect (the main use case for that is probably debugging; you may want to reload module-alsa-card with different parameters than what module-udev-detect used). I propose the following solution: module-udev-detect will still load module-alsa-card instances using pa_module_load() like before, but pa_alsa_card objects will be created too. When module-alsa-card is loaded, it creates a pa_alsa_card instance and adds it to a registry from which module-udev-detect can look it up using the module index as the key. That way users still can unload cards, and module-udev-detect still has access to the pa_alsa_card API. -- Tanu
