Re: [PATCH v3 2/4] media: synopsys: hdmirx: add HDMI audio capture support

[Igor Paunovic]

Hi Dmitry,

Great to hear it works on the 5B -- thanks for testing!

Agreed on the -EBUSY guard, done in my tree exactly as you wrote it.
It also supersedes the suspend cancel/re-arm I had queued from the
bot review: with suspend refused while audio_streaming is set, the
worker can never be armed at suspend time, so those hunks are
dropped.

v4 follows shortly with this plus Sebastian's dts restructuring
(shared disabled-by-default card in rk3588-extra.dtsi, renamed to
"RK3588 HDMI-IN") and Krzysztof's binding comments (dai-common.yaml
reference + unevaluatedProperties).

Igor

On Mon, Jul 20, 2026 at 3:43 AM Dmitry Osipenko
<dmitry.osipenko@xxxxxxxxxxxxx> wrote:
>
> On 7/18/26 11:57, Igor Paunovic wrote:
> > The Synopsys DesignWare HDMI RX controller extracts the audio stream
> > embedded in the incoming HDMI signal and feeds it to an on-SoC I2S
> > controller. Expose it as an ALSA capture device by registering the
> > generic hdmi-codec as a child of the controller, so that a
> > simple-audio-card in the device tree can bind the HDMI RX audio DAI.
> >
> > The sample rate is recovered from the ACR N/CTS values together with the
> > measured TMDS character rate. A periodic worker keeps the local audio
> > reference clock locked to the source by nudging it in small ppm steps to
> > hold the audio FIFO fill level near its target, which avoids FIFO
> > under/overflow and the resulting dropped samples.
> >
> > Signed-off-by: Igor Paunovic <royalnet026@xxxxxxxxx>
> > ---
> > Changes in v3:
> > - restore the v1 audio teardown in remove(): audio_shutdown() already
> >   stops the worker when the stream closes, so the extra flag clear
> >   and trailing cancel added in v2 were redundant (Dmitry Osipenko)
> > - rename the ACR read locals and add a comment documenting the
> >   register byte packing
> > - drop the get_dai_id stub so OF-graph cards resolve the DAI index
> >   from the reg property
> >
> > Changes in v2:
> > - register the S/PDIF DAI so the indexes match the binding and reject
> >   it with -EOPNOTSUPP until wired up (Sebastian Reichel)
> > - use platform_device_register_data() and drop the fixed 32-bit DMA
> >   mask (Dmitry Osipenko)
> > - don't leave an ERR_PTR in audio_pdev on registration failure
> > - fix teardown ordering in remove()
> > - stop the worker before reprogramming shared state in hw_params()
> > - look up the "audio" clock by name instead of indexing clks[1]
> > - keep the worker on system_unbound_wq when re-arming
> >
> >  .../platform/synopsys/hdmirx/snps_hdmirx.c    | 271 ++++++++++++++++++
> >  .../platform/synopsys/hdmirx/snps_hdmirx.h    |   8 +
> >  2 files changed, 279 insertions(+)
>
> Works well on 5b, thanks. Only one additional review comment:
>
> Please update hdmirx_suspend() to return -EBUSY if audio_streaming=true.
>
> ```
> static __maybe_unused int hdmirx_suspend(struct device *dev)
> {
>         struct snps_hdmirx_dev *hdmirx_dev = dev_get_drvdata(dev);
>
>         if (READ_ONCE((hdmirx_dev->audio_streaming)))
>                 return -EBUSY;
> ```
>
> --
> Best regards,
> Dmitry