Re: [RFC PATCH 1/8] ASoC: SDCA: hw_params: program upstream Input Terminals for OT DAI

[Srinivas Kandagatla]

On 7/24/26 2:14 PM, Charles Keepax wrote:
> On Thu, Jul 23, 2026 at 12:42:11AM +0100, Srinivas Kandagatla wrote:
>> For a capture stream the DAI is the Output Terminal so
>> sdca_asoc_hw_params() only programs the OT itself: cluster, clock
>> and Usage.  The upstream Input Terminals that actually source the
>> audio never get their Usage, ClusterIndex or clock programmed, so
>> the power domain comes up but no samples are produced.
>>
>> Walk the source graph from the OT and program every Input Terminal
>> reachable through it.
> 
> What was the thinking with respect to the units in the middle?

As per $6.3.2.1 and 6.3.2.2
FUs does not modify the cluster, its transparent to cluster, Output Pin
uses same cluster as input pin

--srini
> It's not clear to me things are quite as simple as we can copy the
> cluster from the output terminal to the input terminal. Various
> entities in the middle could change the cluster, such as CRUs,
> MPFUs, UDMPUs. Also possibly SUs to consider too, since they
> may change which ITs are actually connected at that point in time,
> although potentially an argument to be made that programming the
> unconnected ones would have no ill effects I guess.
> 
> Any thoughts as well on the propogation of the clock and usage.
> Its a little less clear to me from the spec that they are even
> intended to propogate in this fashion, although it does seem
> fairly logical to me.
> 
> Thanks,
> Charles