[alsa-devel] max channels of 3 jacks 6 channels motherboard using model=auto realtek codec

[Takashi Iwai]

At Sun, 10 Jul 2011 08:47:46 +0200,
Takashi Iwai wrote:
> 
> At Sun, 10 Jul 2011 11:31:44 +0800,
> Raymond Yau wrote:
> > 
> > 2011/7/6 Takashi Iwai <tiwai at suse.de>:
> > > At Wed, 6 Jul 2011 11:53:47 +0800,
> > > Raymond Yau wrote:
> > >>
> > >> Refer to commit ce764ab22e40a046065c9417ee5f04ad2a816ac1
> > >>
> > >> ALSA: hda - Add channel-mode support to Realtek auto-parser
> > >>
> > >> It seem that max channel is six instead of two when the channel mode
> > >> is 2ch for those 3 jacks motherboard
> > >>
> > >> using hda-emu and alsa-info from
> > >> http://thread.gmane.org/gmane.linux.alsa.devel/86816
> > >>
> > >> > PCM 0 p 44100 2 16
> > >> Open PCM ALC887 Analog for play
> > >> Available PCM parameters:
> > >>   channels: 2/6
> > >>   formats: S16_LE S32_LE
> > >>   rates: 44100 48000 96000 192000
> > >> Prepare PCM, rate=44100, channels=2, format=16 bits
> > >>
> > >>
> > >> because
> > >>
> > >>       spec->multiout.max_channels = spec->multiout.num_dacs * 2;
> > >>
> > >> is assigned after  alc_auto_add_multi_channel_mode() increase
> > >> spec->multiout.num_dacs from 1 to 3
> > >>
> > >>               spec->multiout.num_dacs = num_pins + 1;
> > >
> > > Right, and this is intentional.  Since there should be enough amount
> > > of DACs, the driver keeps using the surround DACs statically.
> > > In that way, apps can keep opening the device in the surround mode
> > > while user can switch the outputs on the fly via channel-mode mixer
> > > enum.
> > >
> > >
> > 
> > How can the driver support 6 channels when the input jacks have not
> > been retasked as output ?
> 
> Even if the pins aren't retasked, DACs can receive data.  And then
> you can change the pins and routing on the fly.
> 
> You can open a two-channel PCM stream even if the master or (any
> other) volume is muted.  A similar reason.
> 
> > This behaviour seem different from model=3stack-6ch or
> > model=3stack-6ch-dig or those via codec with smart51 "OFF"

The smart51 case is a bit different (we prefer DAC unused because of
independent HP control), but the 3stack-6ch case is a regression,
indeed.  This was just because of dropped code snippet.
Now I fixed with the patch below.


thanks,

Takashi

---
From: Takashi Iwai <tiwai at suse.de>
Subject: [PATCH] ALSA: hda - Re-add need_dac_fix check for multi-io jacks of
 Realtek codecs

During the rewrite, the check of spec->need_dac_fix and the corresponding
num_dacs change was dropped from the channel-mode control.

This patch re-adds it, and also enables need_dac_fix for ALC880 as default,
as this feature was originally introduced to fix h/w bugs of this chip.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/pci/hda/patch_realtek.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 124c63f..52ce075 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -3196,6 +3196,8 @@ static int alc_auto_ch_mode_put(struct snd_kcontrol *kcontrol,
 	for (i = 0; i < spec->multi_ios; i++)
 		alc_set_multi_io(codec, i, i < ch);
 	spec->multiout.max_channels = spec->ext_channel_count;
+	if (spec->need_dac_fix && !spec->const_channel_count)
+		spec->multiout.num_dacs = spec->multiout.max_channels / 2;
 	return 1;
 }
 
@@ -3642,6 +3644,7 @@ static int patch_alc880(struct hda_codec *codec)
 	codec->spec = spec;
 
 	spec->mixer_nid = 0x0b;
+	spec->need_dac_fix = 1;
 
 	board_config = alc_board_config(codec, ALC880_MODEL_LAST,
 					alc880_models, alc880_cfg_tbl);
-- 
1.7.6