ALSA: hda - hdmi: Disallow unsupported 2ch remapping on NVIDIA codecs

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NVIDIA HDMI codecs do not seem to follow the Audio Sample Packet (ASP)
channel mapping (as set by verb F32h per HDA specification 7.3.3.41)
when playing back 2-channel audio (CEA CA 0x00).

Basically this means that specifying swapped channels for stereo audio
(FR,FL) does not take effect, and e.g. this command plays back on the
wrong channel:
speaker-test -c2 -Dhdmi:CARD=NVidia,DEV=0 -m FR,FL -s1

Multichannel audio is not affected.

This issue has been confirmed to exist on codec 0x10de0015 by me and on
0x10de0040 by Juho Teperi.

Disable 2ch FL/FR channel swapping on all NVIDIA HDMI codecs that use
the standard HDA channel mapping system. Since this is a very minor
functionality loss, we err on the side of disabling it for newer codecs
as well until any future testing confirms that this issue has been
fixed.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Helped-by: Juho Teperi <juho.teperi@iki.fi>
Cc: Aaron Plattner <aplattner@nvidia.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

...

This commit is contained in:

Anssi Hannula 2013-11-03 17:15:00 +02:00 • committed by Takashi Iwai

parent fce762ed9f

commit 611885bc96

1 changed files with 63 additions and 23 deletions

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sound/pci/hda/patch_hdmi.c

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