ALSA: usb-audio: Fix MOTU M-Series quirks

Now that the usb audio driver correctly finds implicit feedback endpoints,
the implicit feedback quirk for the MOTU M-Series is no longer required.

This also removes some unnecessary vendor specific messages from the MOTU
M-Series boot quirk. The removed vendor specific messages turned on vendor
specific interrupts to the host every 32 samples. The only thing the boot
quirk needs to do is wait for 2 seconds.

Tested-by: Dylan Robinson <dylan_robinson@motu.com>
Signed-off-by: Dylan Robinson <dylan_robinson@motu.com>
Link: https://lore.kernel.org/r/20201123085347.19667-42-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/implicit.c

@@ -52,7 +52,6 @@ static const struct snd_usb_implicit_fb_match playback_implicit_fb_quirks[] = {
 	IMPLICIT_FB_FIXED_DEV(0x1397, 0x0001, 0x81, 1), /* Behringer UFX1604 */
 	IMPLICIT_FB_FIXED_DEV(0x1397, 0x0002, 0x81, 1), /* Behringer UFX1204 */
 	IMPLICIT_FB_FIXED_DEV(0x2466, 0x8010, 0x81, 2), /* Fractal Audio Axe-Fx III */
-	IMPLICIT_FB_FIXED_DEV(0x07fd, 0x0008, 0x81, 2), /* MOTU M Series */
 	IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0001, 0x81, 2), /* Solid State Logic SSL2 */
 	IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0002, 0x81, 2), /* Solid State Logic SSL2+ */
 	IMPLICIT_FB_FIXED_DEV(0x0499, 0x172f, 0x81, 2), /* Steinberg UR22C */

sound/usb/quirks.c

@@ -1110,24 +1110,8 @@ free_buf:
 
 static int snd_usb_motu_m_series_boot_quirk(struct usb_device *dev)
 {
-	int ret;
-
-	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
-			      1, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-			      0x0, 0, NULL, 0, 1000);
-
-	if (ret < 0)
-		return ret;
-
 	msleep(2000);
 
-	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
-			      1, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-			      0x20, 0, NULL, 0, 1000);
-
-	if (ret < 0)
-		return ret;
-
 	return 0;
 }