[ALSA] usb-audio: allow output interrupt transfers for MIDI

Allow output interrupt transfers for some MIDI devices that require
them.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 12 insertions, 4 deletions

diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 2bb1834a8c22..4bacb50e9ad9 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/usbmidi.c
@@ -983,8 +983,10 @@ static int snd_usbmidi_out_endpoint_create(struct snd_usb_midi* umidi,
                 snd_usbmidi_out_endpoint_delete(ep);
                 return -ENOMEM;
         }
-        /* we never use interrupt output pipes */
-        pipe = usb_sndbulkpipe(umidi->chip->dev, ep_info->out_ep);
+        if (ep_info->out_interval)
+                pipe = usb_sndintpipe(umidi->chip->dev, ep_info->out_ep);
+        else
+                pipe = usb_sndbulkpipe(umidi->chip->dev, ep_info->out_ep);
         if (umidi->chip->usb_id == USB_ID(0x0a92, 0x1020)) /* ESI M4U */
                 /* FIXME: we need more URBs to get reasonable bandwidth here: */
                 ep->max_transfer = 4;
@@ -996,8 +998,14 @@ static int snd_usbmidi_out_endpoint_create(struct snd_usb_midi* umidi,
                 snd_usbmidi_out_endpoint_delete(ep);
                 return -ENOMEM;
         }
-        usb_fill_bulk_urb(ep->urb, umidi->chip->dev, pipe, buffer,
-                          ep->max_transfer, snd_usbmidi_out_urb_complete, ep);
+        if (ep_info->out_interval)
+                usb_fill_int_urb(ep->urb, umidi->chip->dev, pipe, buffer,
+                                 ep->max_transfer, snd_usbmidi_out_urb_complete,
+                                 ep, ep_info->out_interval);
+        else
+                usb_fill_bulk_urb(ep->urb, umidi->chip->dev,
+                                  pipe, buffer, ep->max_transfer,
+                                  snd_usbmidi_out_urb_complete, ep);
         ep->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
 
         spin_lock_init(&ep->buffer_lock);