On Fri, Oct 11, 2019 at 2:05 PM Daniel Baluta <daniel.baluta@xxxxxxxxx> wrote: > Hi Morimoto-san, > > I'm really confused on what exactly is Front End and Back End. > > Is FE a DAI or a DAI link or part of a DAI link? > > In simple-card.c there is simple_dai_link_of_dpcm function: > > struct snd_soc_dai_link_component *codecs = dai_link->codecs; > > » /* BE is dummy */ > » » codecs->of_node»» = NULL; > » » codecs->dai_name» = "snd-soc-dummy-dai"; > » » codecs->name» » = "snd-soc-dummy"; > > » » /* FE settings */ > » » dai_link->dynamic» » = 1; > » » dai_link->dpcm_merged_format» = 1; > > So, from here it looks like BE/FE are components being part of the same > link. > > Another thing is: > > asoc_simple_canonicalize_platform function where it does say: > > » * DPCM BE can be no platform. > » * Alloced memory will be waste, but not leak. > » */ > » if (!dai_link->platforms->of_node) > » » dai_link->num_platforms = 0; > > But I do want to create a BE with a platform. So, should I try to > revert the following > patch: > > commit 794fcee8da3c0c8a01b08ecad1c181cb0a622868 > Author: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx> > Date: Wed Jul 10 17:01:12 2019 +0900 > > ASoC: simple-card-utils: care no Platform for DPCM > > commit 34614739988ad ("ASoC: soc-core: support dai_link with > platforms_num != 1") supports multi Platform, and > commit 9f3eb91753451 ("ASoC: simple-card-utils: consider CPU-Platform > possibility") removed no Platform from simple-card. > > Multi Platform is now checking both Platform name/of_node are NULL > case. > But in normal case, DPCM be doesn't have Platform. > > > > Basically, what I want to do is: after the DAI link is created to call: > snd_soc_fixup_dai_links_platform_name function to set a proper name > for BE platform. > > The problem is that above mentioned patch sets dai_link->num_platforms = 0; > so even the name is set the platform component is not probed. Hi Daniel, Have you looked into how SOF does it at the time the dai_link elem in topology is parsed? https://github.com/thesofproject/linux/blob/5edcfdf3907354de7a260a451ba611f22c5e6a07/sound/soc/sof/topology.c#L2926 Is this what you are asking about? Thanks, Ranjani > > thanks, > Daniel. > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel