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; } if (!spec->no_multi_io && cfg->line_outs == 1 && cfg->line_out_type != AUTO_PIN_SPEAKER_OUT) { diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c index bdcda6a..717259c 100644 --- a/sound/pci/hda/patch_sigmatel.c +++ b/sound/pci/hda/patch_sigmatel.c @@ -2764,6 +2764,8 @@ static const struct snd_pci_quirk stac92hd83xxx_fixup_tbl[] = { "HP bNB13", STAC_HP_BNB13_EQ), SND_PCI_QUIRK(PCI_VENDOR_ID_HP, 0x190e, "HP ENVY TS", STAC_HP_ENVY_TS_BASS), + SND_PCI_QUIRK(PCI_VENDOR_ID_HP, 0x1967, + "HP ENVY TS", STAC_HP_ENVY_TS_BASS), SND_PCI_QUIRK(PCI_VENDOR_ID_HP, 0x1940, "HP bNB13", STAC_HP_BNB13_EQ), SND_PCI_QUIRK(PCI_VENDOR_ID_HP, 0x1941,