ALSA: oxygen: Xonar DG(X): modify DAC routing

commit 1f91ecc1 upstream.

When selecting the audio output destinations (headphones, FP headphones,
multichannel output), unnecessary I2S channels are digitally muted to
avoid invalid signal levels on the other outputs.
Signed-off-by: Roman Volkov <v1ron@mail.ru>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

sound/pci/oxygen/xonar_dg.c

@@ -294,6 +294,16 @@ static int output_switch_put(struct snd_kcontrol *ctl,
 		oxygen_write16_masked(chip, OXYGEN_GPIO_DATA,
 				      data->output_sel == 1 ? GPIO_HP_REAR : 0,
 				      GPIO_HP_REAR);
+		oxygen_write8_masked(chip, OXYGEN_PLAY_ROUTING,
+				     data->output_sel == 0 ?
+				     OXYGEN_PLAY_MUTE01 :
+				     OXYGEN_PLAY_MUTE23 |
+				     OXYGEN_PLAY_MUTE45 |
+				     OXYGEN_PLAY_MUTE67,
+				     OXYGEN_PLAY_MUTE01 |
+				     OXYGEN_PLAY_MUTE23 |
+				     OXYGEN_PLAY_MUTE45 |
+				     OXYGEN_PLAY_MUTE67);
 	}
 	mutex_unlock(&chip->mutex);
 	return changed;