Re: 2 speakers are assigned to the same DAC, this can't support 4.0/2.1 channles

[Hui Wang <hui.wang@canonical.com>]

On 06/09/2015 07:51 PM, Takashi Iwai wrote:
> At Tue, 09 Jun 2015 17:38:33 +0800,
> hwang4 wrote:
>> I am trying to enable the subwoofer speaker on a HP laptop, on this
>> machine, there are two speakers and one headphone, but the BIOS verb
>> only enabled one speaker(nid 0xd) and one headphone(nid 0xb), I need
>> to use quirk in the kernel driver to configure the second speaker
>> (subwoofer speaker, nid 0x10). Under current alsa driver, the
>> headphone will be assigned a dac (nid 0x13) and the 2 speakers will
>> be assigned a dac (nid 0x14), this assignment is not good since 2
>> speakers share the same dac, this means 2 speakers can't work
>> at the same time to support 4.0/2.1 channels.
>>
>> On another Dell machine with realtek codec, there are also 2 speakers,
>> 1 headphone and 2 dacs, on this machine, 1 speaker and 1 headphone are
>> assigned
>> 1 dac, and the other speaker is assigned another dac, so there is no
>> problem for this machine to support 4.0/2.1 channels.
>>
>> Through debugging, I found on Dell machine, the speaker nid only has
>> one connection to dac (hardwired), so when driver assign dac to it, the
>> map_single() can successfully assign the each dac to the 2 speakers
>> respectively.
>> But on that HP machine, the speaker has multiple connections for dac, the
>> map_single() can't work for this machine.
>>
>>
>> The alsa-info.txt for that HP machine is at
>> http://pastebin.ubuntu.com/11667947/
>> The alsa-info.txt for that Dell machine is at
>> http://pastebin.ubuntu.com/11667982/
>>
>> To fix this problem, I can use the quirk in the driver to make the
>> speaker have
>> only one connection for dac or do some change in the hda_generic.c like
>> below, in
>> your opinion, which one is better or probably you have a different idea
>> to fix this problem?
>>
>> diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c
>> index ac0db16..8194ff1 100644
>> --- a/sound/pci/hda/hda_generic.c
>> +++ b/sound/pci/hda/hda_generic.c
>> @@ -1363,6 +1363,7 @@ static int try_assign_dacs(struct hda_codec
>> *codec, int num_outs,
>>                                   dac = try_dac(codec,
>> get_primary_out(codec, i), pin);
>>                           if (!dac)
>>                                   dac = try_dac(codec, dacs[0], pin);
>>                           if (!dac)
>>                                   dac = try_dac(codec,
>> get_primary_out(codec, i), pin);
>>                           if (dac) {
>> @@ -1762,6 +1763,12 @@ static int fill_and_eval_dacs(struct hda_codec
>> *codec,
>>                   if (err < 0)
>>                           return err;
>>                   badness += err;
>> +               /* if there are 2 speakers and both of them are assigned
>> to the same dac,
>> +                  we need to increase the badness for this situation,
>> because in this situation
>> +                  the 2 speakers can't work together to support 4.0/2.1
>> channels */
>> +               if (cfg->speaker_outs == 2 && err <
>> spec->extra_out_badness->no_dac &&
>> +                   spec->multiout.extra_out_nid[1] == 0)
>> +                       badness += spec->extra_out_badness->no_dac;
> This doesn't look like the correct place to add badness for the
> missing surround speaker.  This function is called for each path, so
> it's evaluated not only for speakers.
>
> A cleaner way would be to prepare a different badness table for the
> speaker, and increase the value for shared_surr.  An untested patch is
> below.
Got it, I will test it soon. Thanks.

>
> Takashi
>
> ---
> diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c
> index ac0db1679f09..ee03fb884426 100644
> --- a/sound/pci/hda/hda_generic.c
> +++ b/sound/pci/hda/hda_generic.c
> @@ -1292,6 +1292,15 @@ const struct badness_table hda_extra_out_badness = {
>   };
>   EXPORT_SYMBOL_GPL(hda_extra_out_badness);
>   
> +static const struct badness_table hda_speaker_out_badness = {
> +	.no_primary_dac = BAD_NO_DAC,
> +	.no_dac = BAD_NO_DAC,
> +	.shared_primary = BAD_NO_EXTRA_DAC,
> +	.shared_surr = BAD_NO_EXTRA_DAC,
> +	.shared_clfe = BAD_SHARED_EXTRA_SURROUND,
> +	.shared_surr_main = BAD_NO_EXTRA_SURR_DAC,
> +};
> +
>   /* get the DAC of the primary output corresponding to the given array index */
>   static hda_nid_t get_primary_out(struct hda_codec *codec, int idx)
>   {
> @@ -1758,7 +1767,7 @@ static int fill_and_eval_dacs(struct hda_codec *codec,
>   				      cfg->speaker_pins,
>   				      spec->multiout.extra_out_nid,
>   				      spec->speaker_paths,
> -				      spec->extra_out_badness);
> +				      spec->speaker_out_badness);
>   		if (err < 0)
>   			return err;
>   		badness += err;
> @@ -4789,6 +4798,8 @@ int snd_hda_gen_parse_auto_config(struct hda_codec *codec,
>   		spec->main_out_badness = &hda_main_out_badness;
>   	if (!spec->extra_out_badness)
>   		spec->extra_out_badness = &hda_extra_out_badness;
> +	if (!spec->speaker_out_badness)
> +		spec->speaker_out_badness = &hda_speaker_out_badness;
>   
>   	fill_all_dac_nids(codec);
>   
> diff --git a/sound/pci/hda/hda_generic.h b/sound/pci/hda/hda_generic.h
> index 56e4139b9032..1f868de1aec4 100644
> --- a/sound/pci/hda/hda_generic.h
> +++ b/sound/pci/hda/hda_generic.h
> @@ -246,6 +246,7 @@ struct hda_gen_spec {
>   	/* badness tables for output path evaluations */
>   	const struct badness_table *main_out_badness;
>   	const struct badness_table *extra_out_badness;
> +	const struct badness_table *speaker_out_badness;
>   
>   	/* preferred pin/DAC pairs; an array of paired NIDs */
>   	const hda_nid_t *preferred_dacs;
> diff --git a/sound/pci/hda/patch_via.c b/sound/pci/hda/patch_via.c
> index 0521be8d46a8..9e9d0456dab7 100644
> --- a/sound/pci/hda/patch_via.c
> +++ b/sound/pci/hda/patch_via.c
> @@ -579,6 +579,7 @@ static int via_parse_auto_config(struct hda_codec *codec)
>   
>   	spec->gen.main_out_badness = &via_main_out_badness;
>   	spec->gen.extra_out_badness = &via_extra_out_badness;
> +	spec->gen.speaker_out_badness = &via_extra_out_badness;
>   
>   	err = snd_hda_parse_pin_defcfg(codec, &spec->gen.autocfg, NULL, 0);
>   	if (err < 0)
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