The function should scan all paths from DACs to OUTS, but like it is just takes the first available DAC. The problem arises here :

if (dac) { spec->private_dac_nids[i] = dac; dac_num++; }

Which correctly adds DAC to used list, but doesn't update the total number of found DACs in spec->multiout.num_dacs; following calls to is_empty_dac() will always return true for already used DACs, making parse_output_path() return always the first one.

Corrected function should be like this :

static int via_auto_fill_dac_nids(struct hda_codec *codec) { struct via_spec *spec = codec->spec; const struct auto_pin_cfg *cfg = &spec->autocfg; int i; hda_nid_t nid;

spec->multiout.dac_nids = spec->private_dac_nids; spec->multiout.num_dacs = 0; for (i = 0; i < cfg->line_outs; i++) { hda_nid_t dac = 0; nid = cfg->line_out_pins[i]; if (!nid) continue; if (parse_output_path(codec, nid, 0, 0, &spec->out_path[i])) dac = spec->out_path[i].path[0]; if (!i && parse_output_path(codec, nid, dac, 1, &spec->out_mix_path)) dac = spec->out_mix_path.path[0]; if (dac) { spec->private_dac_nids[i] = dac; spec->multiout.num_dacs++; } } if (!spec->out_path[0].depth && spec->out_mix_path.depth) { spec->out_path[0] = spec->out_mix_path; spec->out_mix_path.depth = 0; } return 0; }

This one (and a few other changes) allows the subwoofer of asus g75 work correctly. Sorry for not submitting a patch, I'm quite new to alsa; please tell me if/how I should do it.

Ciao Max