ALSA: usb-audio: add implicit fb quirk for MOTU M Series

Message ID
State Accepted
Commit c249177944b650816069f6c49b769baaa94339dc
Headers show
  • ALSA: usb-audio: add implicit fb quirk for MOTU M Series
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Commit Message

Alexander Tsoy Jan. 15, 2020, 3:13 p.m.
This fixes crackling sound during playback.

Signed-off-by: Alexander Tsoy <>

MOTU is known for reusing Product IDs for different devices or different
generations of the device (e.g. MicroBook I/II/IIc shares a single Product
ID). This patch was only tested with M4 audio interface, but the same
Product ID is also used by M2. Hope it will work for M2 as well.

 sound/usb/pcm.c | 4 ++++
 1 file changed, 4 insertions(+)


diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index a11c8150af58..4f1c00615d94 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -348,6 +348,10 @@  static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
 		ep = 0x84;
 		ifnum = 0;
 		goto add_sync_ep_from_ifnum;
+	case USB_ID(0x07fd, 0x0008): /* MOTU M Series */
+		ep = 0x81;
+		ifnum = 2;
+		goto add_sync_ep_from_ifnum;
 	case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
 		/* BOSS Katana amplifiers do not need quirks */
 		return 0;