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

From: Charles Keepax

Date: Mon Jul 27 2026 - 04:34:22 EST


On Fri, Jul 24, 2026 at 05:35:36PM +0100, Srinivas Kandagatla wrote:
> 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

But that section is specific to FUs, all the other units I
listed below do appear to allow cluster changes:

> > entities in the middle could change the cluster, such as CRUs,
> > MPFUs, UDMPUs. Also possibly SUs to consider too, since they

Thanks,
Charles