[alsa-devel] 2 speakers are assigned to the same DAC, this can't support 4.0/2.1 channles

hwang4 hui.wang at canonical.com
Wed Jun 10 06:19:58 CEST 2015



On 2015年06月09日 21:26, Hui Wang wrote:
> 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.
>
Hi Takashi,

Your patch can fix the problem, it works very well.

Thanks,
Hui.
>>
>> 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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>> Alsa-devel at alsa-project.org
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>>
>



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