From 2edb84e3047b93da2f2b234219cdc304df042d9e Mon Sep 17 00:00:00 2001 From: Alexander Tsoy Date: Sat, 29 Feb 2020 18:18:15 +0300 Subject: ALSA: usb-audio: Add support for MOTU MicroBook IIc MicroBook IIc operates in UAC2 mode by default. This patch addresses several issues with it: - MicroBook II and IIc shares the same USB ID. We can distinguish them by interface class. - MaxPacketsOnly attribute is erroneously set in endpoint descriptors. As a result this card produces noise with all sample rates other than 96 KHz. This also causes issues like IOMMU page faults and other problems with host controller. - Sample rate changes takes more than 2 seconds for this device. Clock validity request returns false during that period, so the clock validity quirk is required. Signed-off-by: Alexander Tsoy Link: https://lore.kernel.org/r/20200229151815.14199-1-alexander@tsoy.me Signed-off-by: Takashi Iwai --- sound/usb/pcm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'sound/usb/pcm.c') diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index bd258f1ec2dd..a4e4064f9aee 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -357,7 +357,12 @@ static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs, ep = 0x81; ifnum = 1; goto add_sync_ep_from_ifnum; - case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II */ + case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II/IIc */ + /* MicroBook IIc */ + if (altsd->bInterfaceClass == USB_CLASS_AUDIO) + return 0; + + /* MicroBook II */ ep = 0x84; ifnum = 0; goto add_sync_ep_from_ifnum; -- cgit v1.2.3