Merge branch 'topic/usb-audio' into for-linus

* topic/usb-audio:
  ALSA: usb-audio - Fix types taken in min()
  sound: usb-audio: do not make URBs longer than sync packet interval
  sound: usb-audio: add MIDI drain callback
  sound: usb-audio: use multiple output URBs
  sound: usb-audio: use multiple input URBs
  sound: usb-audio: Xonar U1 digital output support

sound/usb/usbaudio.c

@@ -1083,6 +1083,8 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri
 	} else
 		urb_packs = 1;
 	urb_packs *= packs_per_ms;
+	if (subs->syncpipe)
+		urb_packs = min(urb_packs, 1U << subs->syncinterval);
 
 	/* decide how many packets to be used */
 	if (is_playback) {

sound/usb/usbmixer.c

@@ -86,6 +86,7 @@ struct usb_mixer_interface {
 	u8 rc_buffer[6];
 
 	u8 audigy2nx_leds[3];
+	u8 xonar_u1_status;
 };
 
 
@@ -2042,6 +2043,58 @@ static void snd_audigy2nx_proc_read(struct snd_info_entry *entry,
 	}
 }
 
+static int snd_xonar_u1_switch_get(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
+
+	ucontrol->value.integer.value[0] = !!(mixer->xonar_u1_status & 0x02);
+	return 0;
+}
+
+static int snd_xonar_u1_switch_put(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
+	u8 old_status, new_status;
+	int err, changed;
+
+	old_status = mixer->xonar_u1_status;
+	if (ucontrol->value.integer.value[0])
+		new_status = old_status | 0x02;
+	else
+		new_status = old_status & ~0x02;
+	changed = new_status != old_status;
+	err = snd_usb_ctl_msg(mixer->chip->dev,
+			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x08,
+			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
+			      50, 0, &new_status, 1, 100);
+	if (err < 0)
+		return err;
+	mixer->xonar_u1_status = new_status;
+	return changed;
+}
+
+static struct snd_kcontrol_new snd_xonar_u1_output_switch = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Digital Playback Switch",
+	.info = snd_ctl_boolean_mono_info,
+	.get = snd_xonar_u1_switch_get,
+	.put = snd_xonar_u1_switch_put,
+};
+
+static int snd_xonar_u1_controls_create(struct usb_mixer_interface *mixer)
+{
+	int err;
+
+	err = snd_ctl_add(mixer->chip->card,
+			  snd_ctl_new1(&snd_xonar_u1_output_switch, mixer));
+	if (err < 0)
+		return err;
+	mixer->xonar_u1_status = 0x05;
+	return 0;
+}
+
 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
 			 int ignore_error)
 {
@@ -2084,6 +2137,13 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
 					      snd_audigy2nx_proc_read);
 	}
 
+	if (mixer->chip->usb_id == USB_ID(0x0b05, 0x1739) ||
+	    mixer->chip->usb_id == USB_ID(0x0b05, 0x1743)) {
+		err = snd_xonar_u1_controls_create(mixer);
+		if (err < 0)
+			goto _error;
+	}
+
 	err = snd_device_new(chip->card, SNDRV_DEV_LOWLEVEL, mixer, &dev_ops);
 	if (err < 0)
 		goto _error;