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

On Fri, Jul 24, 2026 at 02:14:50PM +0100, 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?
> 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.

Although actually maybe 4.4.5.2? That does seem to suggest the
clock should progogate sensibly.

Thanks,
Charles