Re: [PATCH] ALSA: hda: codecs: hdmi: disable keep-alive before audio format change

[Takashi Iwai <tiwai@suse.de>]

On Wed, 15 Jul 2026 20:06:10 +0200,
Kai Vehmanen wrote:
> 
> When a keep-alive (KAE) silent stream is active on an Intel HDMI/DP
> codec, opening a real PCM stream reprograms the converter format and the
> audio infoframe in snd_hda_hdmi_generic_pcm_prepare(). Part of that
> reprogramming - the converter channel count and the channel mapping in
> snd_hda_hdmi_setup_audio_infoframe() - is not safe to do while a
> keep-alive stream is active. This is most visible when switching to a
> multichannel PCM configuration, where the active channel count actually
> changes. In that case the newly opened PCM stream plays no sound.
> 
> Add an optional hdmi_ops .prepare hook, called at the start of the
> PCM prepare sequence (before the format and infoframe are touched), and
> implement it for HSW+ to release keep-alive. Keep-alive is then
> re-enabled as before once the new stream has been set up, in the
> setup_stream op.
> 
> Fixes: 15175a4f2bbb ("ALSA: hda/hdmi: add keep-alive support for ADL-P and DG2")
> Reported-by: Alexander Kaplan <alexander.kaplan@sms-medipool.de>
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/8412
> Tested-by: Alexander Kaplan <alexander.kaplan@sms-medipool.de>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Applied now.  Thanks.


Takashi