ALSA: snd-usb-us122l: Fix MIDI output
The US-122L always reads 9 bytes per urb unless they are set to 0xFD.
Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Cc: stable@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index d7021cb..db2dc5f 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -850,8 +850,8 @@
return;
}
- memset(urb->transfer_buffer + count, 0xFD, 9 - count);
- urb->transfer_buffer_length = count;
+ memset(urb->transfer_buffer + count, 0xFD, ep->max_transfer - count);
+ urb->transfer_buffer_length = ep->max_transfer;
}
static struct usb_protocol_ops snd_usbmidi_122l_ops = {
@@ -1295,6 +1295,13 @@
case USB_ID(0x1a86, 0x752d): /* QinHeng CH345 "USB2.0-MIDI" */
ep->max_transfer = 4;
break;
+ /*
+ * Some devices only work with 9 bytes packet size:
+ */
+ case USB_ID(0x0644, 0x800E): /* Tascam US-122L */
+ case USB_ID(0x0644, 0x800F): /* Tascam US-144 */
+ ep->max_transfer = 9;
+ break;
}
for (i = 0; i < OUTPUT_URBS; ++i) {
buffer = usb_alloc_coherent(umidi->dev,