Re: [RFC v2 0/2] ASoC: prepare streams on codec-to-codec links

[Jerome Brunet <jbrunet@xxxxxxxxxxxx>]

On Fri 10 Jan 2025 at 22:07, Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote:

> Hello,
>
> the DRM subsystem has recently gained a HDMI audio codec framework [0].
> This is already queued for Linux 6.14.
>
> I want to implement a HDMI controller driver for the Amlogic
> Meson8/8b/8m2 SoCs using the DRM HDMI audio codec framework. Internally
> the DRM HDMI audio codec framework relies on hdmi-codec's .prepare
> callback to be called. This unfortunately is not happening on Amlogic
> Meson8/8b/8m2 platforms [1].
>
> Jerome suggested that this may be because of the codec-to-codec link on
> our Amlogic AIU audio driver [2]. He encouraged me to send this series
> to allow hdmi-codec's .prepare() callback to be called - even on
> platforms that connect it via a codec-to-codec link.
>
> The reason why this series is marked as RFC is that I'm not familiar
> with the ASoC subsystem and lot of the functionality and terminology
> is new to me.
>
> Also I Cc'ed Sylwester Nawrocki (Samsung maintainer) as codec-to-codec
> links seem to be most heavily used on Samsung and Amlogic platforms.
>
> Changes since v1 at [3]:
> - updated patch #2 to also prepare the source side of the link for
>   consistency reasons (as suggested by Jerome and Mark)
>
>
> [0] https://lore.kernel.org/dri-devel/20241224-drm-bridge-hdmi-connector-v10-0-dc89577cd438@xxxxxxxxxx/
> [1] https://lore.kernel.org/linux-amlogic/CAFBinCDdiJ3UNVUcShjq=7U2=oUwT3ciYdKSuZ5TdcrikxFBpg@xxxxxxxxxxxxxx/
> [2] https://lore.kernel.org/linux-amlogic/1ja5c4b4rt.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
> [3] https://lore.kernel.org/linux-sound/20250106141316.375984-1-martin.blumenstingl@xxxxxxxxxxxxxx/
>
>
> Martin Blumenstingl (2):
>   ASoC: soc-dai: add snd_soc_dai_prepare() and use it internally
>   ASoC: dapm: add support for preparing streams

Reviewed-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>

Not sure the RFC tag was necessary, this could go in as it is I suppose.
Thanks Martin !

>
>  include/sound/soc-dai.h |  3 +++
>  sound/soc/soc-dai.c     | 27 +++++++++++++++++++--------
>  sound/soc/soc-dapm.c    | 12 ++++++++++++
>  3 files changed, 34 insertions(+), 8 deletions(-)

-- 
Jerome