[alsa-devel] Intel8x0 8 channel sound

Andrew Boettcher a.boettcher at gmail.com
Mon Feb 18 14:21:54 CET 2008


On Feb 18, 2008 1:59 AM, Takashi Iwai <tiwai at suse.de> wrote:

> At Sun, 17 Feb 2008 14:31:11 -0500,
> Andrew Boettcher wrote:
> >
> > [1  <multipart/alternative (7bit)>]
> > [1.1  <text/plain; ISO-8859-1 (7bit)>]
> >
> > [1.2  <text/html; ISO-8859-1 (7bit)>]
> > On Feb 17, 2008 1:53 PM, Andrew Boettcher <a.boettcher at gmail.com> wrote:
> >
> >     On Feb 15, 2008 11:01 AM, Takashi Iwai <tiwai at suse.de> wrote:
> >
> >         At Thu, 14 Feb 2008 15:02:04 -0500,
> >         Andrew Boettcher wrote:
> >         >
> >         > For some intel 8x0 cards there is 8 channel sound (such as the
> >         ALC850 chip
> >         > on NFORCE 4 boards), and this has not been patched yet though
> the
> >         patch has
> >         > been on the bug tracker.  Here it is again updated for 1.0.16.
> >          There is
> >         > also a patch for the configuration in alsa-lib for cards/
> >         NFORCE.conf.  I
> >         > have been patching my sources every time I update my kernel, I
> >         figured it
> >         > was time for someone to actually submit this somewhere else.
>  The
> >         patch was
> >         > written by Martin Ellis.
> >
> >         Thanks for submitting this.  I haven't checked that issue.
> >
> >         The change is almost OK.  One thing to be fixed is the
> enablement of
> >         chip->multi8.  It's unconditionally enabled together with
> multi6.
> >
> >         I think we should add a new bitflag in ac97_codec->flags to
> indicate
> >         that the codec supports 8 channels.  Also,
> ac97_channel_mode_info()
> >         shouldn't be unconditionally 8-channels, too.  It should check
> the
> >         8-channel capability as well.
> >
> >         Do you know which audio controller model supports 7.1 output?
>  We may
> >         need to check the chip model eventualy for 7.1-enablement.
> >         Certainly the earlier version of controllers don't support 7.1output.
> >         Well, but these are very unlikely with ALC850 chip, so maybe it
> >         doesn't matter... :)
> >
> >         The below is a quick-fixed patch.  Could you try it?
> >
> >         Takashi
> >
> >         ---
> >
> >         diff -r 362cee3efa84 include/ac97_codec.h
> >         --- a/include/ac97_codec.h      Fri Feb 15 16:43:11 2008 +0100
> >         +++ b/include/ac97_codec.h      Fri Feb 15 16:59:51 2008 +0100
> >         @@ -397,6 +397,7 @@
> >          #define AC97_HAS_NO_TONE       (1<<16) /* no Tone volume */
> >          #define AC97_HAS_NO_STD_PCM    (1<<17) /* no standard AC97 PCM
> volume
> >         and mute */
> >          #define AC97_HAS_NO_AUX                (1<<18) /* no standard
> AC97
> >         AUX volume and mute */
> >         +#define AC97_HAS_8CH           (1<<19) /* supports 8-channel
> output *
> >         /
> >
> >          /* rates indexes */
> >          #define AC97_RATES_FRONT_DAC   0
> >         diff -r 362cee3efa84 pci/ac97/ac97_patch.c
> >         --- a/pci/ac97/ac97_patch.c     Fri Feb 15 16:43:11 2008 +0100
> >         +++ b/pci/ac97/ac97_patch.c     Fri Feb 15 16:59:51 2008 +0100
> >         @@ -114,10 +114,9 @@ static int ac97_surround_jack_mode_put(s
> >
> >          static int ac97_channel_mode_info(struct snd_kcontrol
> *kcontrol,
> >         struct snd_ctl_elem_info *uinfo)
> >          {
> >         -       static const char *texts[] = { "2ch", "4ch", "6ch" };
> >         -       if (kcontrol->private_value)
> >         -               return ac97_enum_text_info(kcontrol, uinfo,
> texts, 2);
> >         /* 4ch only */
> >         -       return ac97_enum_text_info(kcontrol, uinfo, texts, 3);
> >         +       static const char *texts[] = { "2ch", "4ch", "6ch",
> "8ch" };
> >         +       return ac97_enum_text_info(kcontrol, uinfo, texts,
> >         +                                  kcontrol->private_value);
> >          }
> >
> >          static int ac97_channel_mode_get(struct snd_kcontrol *kcontrol,
> >         struct snd_ctl_elem_value *ucontrol)
> >         @@ -133,13 +132,8 @@ static int ac97_channel_mode_put(struct
> >                struct snd_ac97 *ac97 = snd_kcontrol_chip(kcontrol);
> >                unsigned char mode = ucontrol->value.enumerated.item[0];
> >
> >         -       if (kcontrol->private_value) {
> >         -               if (mode >= 2)
> >         -                       return -EINVAL;
> >         -       } else {
> >         -               if (mode >= 3)
> >         -                       return -EINVAL;
> >         -       }
> >         +       if (mode >= kcontrol->private_value)
> >         +               return -EINVAL;
> >
> >                if (mode != ac97->channel_mode) {
> >                        ac97->channel_mode = mode;
> >         @@ -158,6 +152,7 @@ static int ac97_channel_mode_put(struct
> >                        .get = ac97_surround_jack_mode_get, \
> >                        .put = ac97_surround_jack_mode_put, \
> >                }
> >         +/* 6ch */
> >          #define AC97_CHANNEL_MODE_CTL \
> >                { \
> >                        .iface  = SNDRV_CTL_ELEM_IFACE_MIXER, \
> >         @@ -165,7 +160,9 @@ static int ac97_channel_mode_put(struct
> >                        .info = ac97_channel_mode_info, \
> >                        .get = ac97_channel_mode_get, \
> >                        .put = ac97_channel_mode_put, \
> >         +               .private_value = 3, \
> >                }
> >         +/* 4ch */
> >          #define AC97_CHANNEL_MODE_4CH_CTL \
> >                { \
> >                        .iface  = SNDRV_CTL_ELEM_IFACE_MIXER, \
> >         @@ -173,7 +170,17 @@ static int ac97_channel_mode_put(struct
> >                        .info = ac97_channel_mode_info, \
> >                        .get = ac97_channel_mode_get, \
> >                        .put = ac97_channel_mode_put, \
> >         -               .private_value = 1, \
> >         +               .private_value = 2, \
> >         +       }
> >         +/* 8ch */
> >         +#define AC97_CHANNEL_MODE_8CH_CTL \
> >         +       { \
> >         +               .iface  = SNDRV_CTL_ELEM_IFACE_MIXER, \
> >         +               .name   = "Channel Mode", \
> >         +               .info = ac97_channel_mode_info, \
> >         +               .get = ac97_channel_mode_get, \
> >         +               .put = ac97_channel_mode_put, \
> >         +               .private_value = 4, \
> >                }
> >
> >          static inline int is_surround_on(struct snd_ac97 *ac97)
> >         @@ -208,6 +215,11 @@ static inline int is_shared_micin(struct
> >          static inline int is_shared_micin(struct snd_ac97 *ac97)
> >          {
> >                return !ac97->indep_surround && !is_clfe_on(ac97);
> >         +}
> >         +
> >         +static inline int alc850_is_aux_back_surround(struct snd_ac97
> *ac97)
> >         +{
> >         +       return is_surround_on(ac97);
> >          }
> >
> >         @@ -2816,10 +2828,12 @@ static int patch_alc655(struct snd_ac97
> >
> >          #define AC97_ALC850_JACK_SELECT        0x76
> >          #define AC97_ALC850_MISC1      0x7a
> >         +#define AC97_ALC850_MULTICH    0x6a
> >
> >          static void alc850_update_jacks(struct snd_ac97 *ac97)
> >          {
> >                int shared;
> >         +       int aux_is_back_surround;
> >
> >                /* shared Line-In / Surround Out */
> >                shared = is_shared_surrout(ac97);
> >         @@ -2837,13 +2851,18 @@ static void alc850_update_jacks(struct s
> >                /* MIC-IN = 1, CENTER-LFE = 5 */
> >                snd_ac97_update_bits(ac97, AC97_ALC850_JACK_SELECT, 7 <<
> 4,
> >                                     shared ? (5<<4) : (1<<4));
> >         +
> >         +       aux_is_back_surround =
> alc850_is_aux_back_surround(ac97);
> >         +       /* Aux is Back Surround */
> >         +       snd_ac97_update_bits(ac97, AC97_ALC850_MULTICH, 1 << 10,
> >         +                            aux_is_back_surround ? (1<<10) : (0
> >         <<10));
> >          }
> >
> >          static const struct snd_kcontrol_new snd_ac97_controls_alc850[]
> = {
> >                AC97_PAGE_SINGLE("Duplicate Front", AC97_ALC650_MULTICH,
> 0, 1,
> >         0, 0),
> >                AC97_SINGLE("Mic Front Input Switch",
> AC97_ALC850_JACK_SELECT,
> >         15, 1, 1),
> >                AC97_SURROUND_JACK_MODE_CTL,
> >         -       AC97_CHANNEL_MODE_CTL,
> >         +       AC97_CHANNEL_MODE_8CH_CTL,
> >          };
> >
> >          static int patch_alc850_specific(struct snd_ac97 *ac97)
> >         @@ -2878,6 +2897,7 @@ static int patch_alc850(struct snd_ac97
> >                   spdif-in monitor off, spdif-in PCM off
> >                   center on mic off, surround on line-in off
> >                   duplicate front off
> >         +          NB default bit 10=0 = Aux is Capture, not Back
> Surround
> >                */
> >                snd_ac97_write_cache(ac97, AC97_ALC650_MULTICH, 1<<15);
> >                /* SURR_OUT: on, Surr 1kOhm: on, Surr Amp: off, Front
> 1kOhm:
> >         off
> >         diff -r 362cee3efa84 pci/intel8x0.c
> >         --- a/pci/intel8x0.c    Fri Feb 15 16:43:11 2008 +0100
> >         +++ b/pci/intel8x0.c    Fri Feb 15 16:59:51 2008 +0100
> >         @@ -155,7 +155,8 @@ DEFINE_REGSET(SP, 0x60);    /* SPDIF out */
> >          #define   ICH_PCM_SPDIF_69     0x80000000      /* s/pdif pcm on
> slots
> >         6&9 */
> >          #define   ICH_PCM_SPDIF_1011   0xc0000000      /* s/pdif pcm on
> slots
> >         10&11 */
> >          #define   ICH_PCM_20BIT                0x00400000      /*
> 20-bit
> >         samples (ICH4) */
> >         -#define   ICH_PCM_246_MASK     0x00300000      /* 6 channels
> (not all
> >         chips) */
> >         +#define   ICH_PCM_246_MASK     0x00300000      /* channels (not
> all
> >         chips) */
> >         +#define   ICH_PCM_8            0x00300000      /* 8 channels
> (not all
> >         chips) */
> >          #define   ICH_PCM_6            0x00200000      /* 6 channels
> (not all
> >         chips) */
> >          #define   ICH_PCM_4            0x00100000      /* 4 channels
> (not all
> >         chips) */
> >          #define   ICH_PCM_2            0x00000000      /* 2 channels
> (stereo)
> >         */
> >         @@ -382,6 +383,7 @@ struct intel8x0 {
> >
> >                unsigned multi4: 1,
> >                         multi6: 1,
> >         +                multi8 :1,
> >                         dra: 1,
> >                         smp20bit: 1;
> >                unsigned in_ac97_init: 1,
> >         @@ -995,6 +997,8 @@ static void snd_intel8x0_setup_pcm_out(s
> >                                cnt |= ICH_PCM_4;
> >                        else if (runtime->channels == 6)
> >                                cnt |= ICH_PCM_6;
> >         +               else if (runtime->channels == 8)
> >         +                       cnt |= ICH_PCM_8;
> >                        if (chip->device_type == DEVICE_NFORCE) {
> >                                /* reset to 2ch once to keep the 6
> channel data
> >         in alignment,
> >                                 * to start from Front Left always
> >         @@ -1104,6 +1108,16 @@ static struct snd_pcm_hw_constraint_list
> >                .mask = 0,
> >          };
> >
> >         +static unsigned int channels8[] = {
> >         +       2, 4, 6, 8,
> >         +};
> >         +
> >         +static struct snd_pcm_hw_constraint_list
> hw_constraints_channels8 = {
> >         +       .count = ARRAY_SIZE(channels8),
> >         +       .list = channels8,
> >         +       .mask = 0,
> >         +};
> >         +
> >          static int snd_intel8x0_pcm_open(struct snd_pcm_substream
> *substream,
> >         struct ichdev *ichdev)
> >          {
> >                struct intel8x0 *chip =
> snd_pcm_substream_chip(substream);
> >         @@ -1134,7 +1148,12 @@ static int snd_intel8x0_playback_open(st
> >                if (err < 0)
> >                        return err;
> >
> >         -       if (chip->multi6) {
> >         +       if (chip->multi8) {
> >         +               runtime->hw.channels_max = 8;
> >         +               snd_pcm_hw_constraint_list(runtime, 0,
> >         +
> >          SNDRV_PCM_HW_PARAM_CHANNELS,
> >         +
>  &hw_constraints_channels8);
> >         +       } else if (chip->multi6) {
> >                        runtime->hw.channels_max = 6;
> >                        snd_pcm_hw_constraint_list(runtime, 0,
> >         SNDRV_PCM_HW_PARAM_CHANNELS,
> >
> &hw_constraints_channels6);
> >         @@ -2195,8 +2214,11 @@ static int __devinit snd_intel8x0_mixer(
> >                }
> >                if (pbus->pcms[0].r[0].slots & (1 <<
> AC97_SLOT_PCM_SLEFT)) {
> >                        chip->multi4 = 1;
> >         -               if (pbus->pcms[0].r[0].slots & (1 <<
> AC97_SLOT_LFE))
> >         +               if (pbus->pcms[0].r[0].slots & (1 <<
> AC97_SLOT_LFE)) {
> >                                chip->multi6 = 1;
> >         +                       if (chip->ac97[0]->flags & AC97_HAS_8CH)
> >         +                               chip->multi8 = 1;
> >         +               }
> >                }
> >                if (pbus->pcms[0].r[1].rslots[0]) {
> >                        chip->dra = 1;
> >
> >     It does not work 8 channel.  I found the problem though.  in line
> 2219 of
> >     the patched pci/intel8x0.c it checks for the flag AC97_HAS_8CH
> >     This flag is never set anywhere.  where would be the appropriate
> place?
> >
> >                 if (chip->ac97[0]->flags & AC97_HAS_8CH)
> >                     chip->multi8 = 1;
> >
> >     Andrew Boettcher
> >
> > I went ahead and  made a new patch, attached.  I put the flag in
> patch_alc850
> > () in pci/ac97/ac97_patch.c
>
> Yes, that's the right place.
>
> > The only issue I see now is the imbalanced volumes, nothing a .asoundrc
> can't
> > fix.  I wonder if the DAC volumes are maxed for the side and rear DACs?
>  In
> > the code it only maxes 2 of them.  I don't have a data sheet to see how
> to max
> > the others if they are maxed, or what the deal is.
>
> Hm, could you elaborate?  Which DAC volume doesn't get the maximum
> volume and which volume can be in the max level (supposed 0dB) via
> which AC97 register / ALSA mixer control right now?
>
>
> Takashi
>


After reading the datasheet AC97_PCM is _only_ the front DAC volume.  The
center/LFE and Surround DAC volumes are forced to 0x0808 (+0dB gain).  The
rear surround DAC has no method of controlling the DAC volume, it only has
its normal volume control that it shares with aux in.  I am going to change
my own source to remove the PCM volume control and just force it to 0x0808,
but not all people want balanced sound so I guess I will keep that patch to
myself.  I would however recommend setting the AC97_PCM register to 0x0808
by default to match the other DAC volumes.  Normally volumes are all muted
at first by default, so I don't know how this would be done.  The DACs go up
to +12dB gain, so max PCM volume is what made my front speakers much louder
than the center/LFE side and rear.

Andrew


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