Re: [PATCH 12/12] arm64: dts: qcom: qcs6490-radxa-dragon-q6a: add LPASS CPU audio variant

[Konrad Dybcio]

On 4/7/26 5:20 PM, Xilin Wu wrote:
> Add a qcs6490-radxa-dragon-q6a-lpass-cpu.dts variant for debugging and
> bring-up of the host-controlled LPASS audio path on the Radxa Dragon
> Q6A.
> 
> This variant enables the LPASS blocks and codec macros needed by the
> lpass-cpu driver, wires WCD9380 playback/capture and DisplayPort audio
> to the LPASS CDC DMA and DP interfaces, and disables remoteproc_adsp so
> that the audio hardware is owned directly by Linux.
> 
> This DTB is an optional configuration for systems booted with the kernel
> running at EL2, where direct CPU access to the LPASS hardware is
> available. It is useful for users who need low-latency and fully
> controllable audio.

I believe on Chrome platforms it was done this way because at some point
it was determined that they would specifically like not to use the DSP.

I think this is more of a hack than anything else.. but at the end of the
commit message you mention low latency - is the impact actually measurable?

Konrad