ALSA: hda/hdmi: add keep-alive support for ADL-P and DG2

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Implement HDA keep alive (KAE) support for Intel display codecs. When no
audio stream is active, the display codec will provide a continuous clock
and a valid but silent audio stream to any connected HDMI/DP receiver.
Without this, upon starting a new playback stream, initial samples may be
lost as many receivers require time to initialize for new clock.

This is a new feature in Intel AlderLake-P display codec implementation
and replaces the Intel i915 silent-stream extension that has been used
on older hardware. Main benefit of the new method is that codec no longer
needs to be kept in D0 power state.

This patch depends on commit 112a87c48e ("drm/i915/display: program
audio CDCLK-TS for keepalives").

[ a minor coding-style fix by tiwai ]

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Jyri Sarha <jyri.sarha@intel.com>
Link: https://lore.kernel.org/r/20220216172405.3994959-1-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

...

This commit is contained in:

Kai Vehmanen 2022-02-16 19:24:05 +02:00 • committed by Takashi Iwai

parent a9f73b06ff

commit 15175a4f2b

2 changed files with 126 additions and 49 deletions

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19

sound/pci/hda/Kconfig

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156

sound/pci/hda/patch_hdmi.c

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