ALSA: Au88x0 - Support 4 channels playback when AC97 codecs has SDAC bit

- Check SDAC bit of AC97 codec for supporting 4 channels playback.
Signed-off-by: Raymond Yau <superquad.vortex2@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/au88x0/au88x0.c

@@ -268,6 +268,11 @@ snd_vortex_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
 		card->shortname, chip->io, chip->irq);
 
 	// (4) Alloc components.
+	err = snd_vortex_mixer(chip);
+	if (err < 0) {
+		snd_card_free(card);
+		return err;
+	}
 	// ADB pcm.
 	if ((err = snd_vortex_new_pcm(chip, VORTEX_PCM_ADB, NR_ADB)) < 0) {
 		snd_card_free(card);
@@ -299,11 +304,6 @@ snd_vortex_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
 		return err;
 	}
 #endif
-	// snd_ac97_mixer and Vortex mixer.
-	if ((err = snd_vortex_mixer(chip)) < 0) {
-		snd_card_free(card);
-		return err;
-	}
 	if ((err = snd_vortex_midi(chip)) < 0) {
 		snd_card_free(card);
 		return err;

sound/pci/au88x0/au88x0_pcm.c

@@ -168,6 +168,7 @@ static int snd_vortex_pcm_open(struct snd_pcm_substream *substream)
 			runtime->hw = snd_vortex_playback_hw_adb;
 #ifdef CHIP_AU8830
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+			VORTEX_IS_QUAD(vortex) &&
 			VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_ADB) {
 			runtime->hw.channels_max = 4;
 			snd_pcm_hw_constraint_list(runtime, 0,