To prepare next week's ALSA-Asoc meeting, I reviewed Liam's dsp-upstream code, and I am a bit unclear on the 'no_host_mode' supported by some DAIs. Apparently these are regular ALSA PCM substreams, except that there are no data exchanges to/from the host. - If these substreams are known, an application can in theory open/close them. How would it know that no data is to be written/read? I would think additional changes are required in alsa-lib? - is this really important that such PCM devices be known in userspace? Or are they declared only so that ALSA controls are enabled for these streams? - along the same lines, how useful is the .pointer routine for such devices? Since no data will be provided by the host, is this really needed? I see it's only meaningful for the low-power playback mode, but I am unsure if the information provided would actually be used by anyone? - what is the meaning of the SND_SOC_DAI_LINK_OPT_HOST definition? It doesn't seem to be updated depending on which back-end is used, so it this really needed? Thanks -Pierre