On Tue, Apr 23, 2024 at 01:38:18PM +0100, Srinivas Kandagatla wrote: > On 23/04/2024 12:59, Johan Hovold wrote: > > It looks like your UCM changes are still muxing the speaker and *each* > > displayport output so that you can only use one device at a time (i.e. > > only Speaker or DP1 or DP2 can be used). > that is true. > > What is the use-case to use more than one audio sink devices at the same > time for a laptops? I can imagine streaming audio and video to a TV (or audio to a soundbar) over DP while playing systems sounds and doing video conferencing using the internal speakers (or the other DP port). > How do you test it? I never tested anything like that on a full desktop > setup. You can select the sink per application in pavucontrol. Just verified that playing audio over the 3.5 mm jack while playing system sounds using the internal speakers works just fine. > > As we discussed off list last week, this seems unnecessarily limited and > > as far as I understood is mostly needed to work around some > > implementation details (not sure why DP1 and DP2 can't be used in > > parallel either). > > It is absolutely possible to run all the streams in parallel from the > Audio hardware and DSP point of view. > > One thing to note is, On Qualcomm DP IP, we can not read/write registers > if the DP port is not connected, which means that we can not send data > in such cases. > > This makes it challenging to work with sound-servers like pipewire or > pulseaudio as they tend to send silence data at very early stages in the > full system boot up, ignoring state of the Jack events. This bit sounds like it can and should be worked around by the driver to avoid hard-coding policy which would prevent use cases such as the ones mentioned above. > > Can you please describe the problem here so that we can discuss this > > before merging an unnecessarily restricted solution which may later be > > harder to change (e.g. as kernel, topology and ucm may again need to be > > updated in lock step). > > > > From what I could tell after a quick look, this series does not > > necessarily depend on muxing things this way, but please confirm that > > too. > > These patches have nothing to do with how we model the muxing in UCM or > in tplg. > > so these can go as it is irrespective of how we want to model the DP > sinks in the UCM or tplg. Thanks for confirming. Johan
