Re: [PATCH v3 3/4] arm64: dts: rockchip: add #sound-dai-cells to the RK3588 HDMI receiver

[Igor Paunovic]

A testing note for anyone trying this out, found while exercising
the series today:

after (re)connecting a source, audio capture currently requires the
video capture path to have been started once -- a cold
`arecord -D hw:...` right after plug-in fails with EIO (the I2S
interface gets no bit clock), while the same command succeeds after
one video STREAMON/STREAMOFF cycle, and keeps working from then on
until the source is re-plugged.

Setting DV timings alone is not sufficient; it does take a real
streaming cycle. So for testing audio, either run a video pipeline
first (e.g. v4l2src ! fakesink for a second) or capture both, which
is the normal use case anyway.

I'm investigating which part of the streaming path opens the audio
packet flow, and will either fix it in v4 (if it turns out to be a
missing enable in the audio path) or send it as a follow-up with a
proper analysis.

Igor

On Sat, Jul 18, 2026 at 10:57 AM Igor Paunovic <royalnet026@xxxxxxxxx> wrote:
>
> The Synopsys HDMI RX controller exposes two digital audio interfaces,
> one for I2S (0) and one for S/PDIF (1). Add the #sound-dai-cells
> property so audio cards can reference them as a codec, as documented
> by the snps,dw-hdmi-rx binding.
>
> Signed-off-by: Igor Paunovic <royalnet026@xxxxxxxxx>
> ---
> New in v3.
>
>  arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi b/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi
> index a264001..fa100e3 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi
> @@ -338,6 +338,7 @@
>                 reset-names = "axi", "apb", "ref", "biu";
>                 rockchip,grf = <&sys_grf>;
>                 rockchip,vo1-grf = <&vo1_grf>;
> +               #sound-dai-cells = <1>;
>                 status = "disabled";
>         };
>
> --
> 2.53.0
>