- dmesg output, 2022-01-14
- clock source workaround is present
- `IMPLICIT_FB_GENERIC_DEV(0x1397, 0x0507),` line under playback_implicit_fb_quirks in /sound/usb/implicit.c (doesn't really change the feedback mode as per previous attempt)
- `modprobe snd_usb_audio dyndbg==p` 
- still non-implicit feedback and stuttering

[48731.161380] usb 3-3: USB disconnect, device number 19
[48759.574239] usbcore: deregistering interface driver snd-usb-audio
[48763.455999] usbcore: registered new interface driver snd-usb-audio
[48774.731400] usb 3-3: new high-speed USB device number 20 using xhci_hcd
[48774.858557] usb 3-3: config 1 has an invalid interface number: 5 but max is 3
[48774.858574] usb 3-3: config 1 has no interface number 3
[48774.859485] usb 3-3: New USB device found, idVendor=1397, idProduct=0507, bcdDevice= 1.00
[48774.859515] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[48774.859531] usb 3-3: Product: UMC202HD 192k
[48774.859543] usb 3-3: Manufacturer: BEHRINGER
[48774.859551] usb 3-3: SerialNumber: 12345678
[48875.327447] usb 3-3: USB disconnect, device number 20
[48890.025235] usbcore: deregistering interface driver snd-usb-audio
[48931.816944] usbcore: registered new interface driver snd-usb-audio
[48937.230569] usb 3-3: new high-speed USB device number 21 using xhci_hcd
[48937.357639] usb 3-3: config 1 has an invalid interface number: 5 but max is 3
[48937.357656] usb 3-3: config 1 has no interface number 3
[48937.358633] usb 3-3: New USB device found, idVendor=1397, idProduct=0507, bcdDevice= 1.00
[48937.358651] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[48937.358658] usb 3-3: Product: UMC202HD 192k
[48937.358664] usb 3-3: Manufacturer: BEHRINGER
[48937.358670] usb 3-3: SerialNumber: 12345678
[49625.890252] usb 3-3: USB disconnect, device number 21
[49627.573706] usbcore: deregistering interface driver snd-usb-audio
[49665.802565] usbcore: registered new interface driver snd-usb-audio
[49672.560875] usb 3-3: new high-speed USB device number 22 using xhci_hcd
[49672.687974] usb 3-3: config 1 has an invalid interface number: 5 but max is 3
[49672.687991] usb 3-3: config 1 has no interface number 3
[49672.689028] usb 3-3: New USB device found, idVendor=1397, idProduct=0507, bcdDevice= 1.00
[49672.689050] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[49672.689062] usb 3-3: Product: UMC202HD 192k
[49672.689070] usb 3-3: Manufacturer: BEHRINGER
[49672.689077] usb 3-3: SerialNumber: 12345678
[49672.692367] usb 3-3: 1:1: found sync_ep=0x84, iface=1, alt=1, implicit_fb=0
[49672.692379] usb 3-3: 1:1: add audio endpoint 0x8
[49672.692409] usb 3-3: Creating new data endpoint #8
[49672.692417] usb 3-3: Creating new sync endpoint #84
[49672.692611] usb 3-3: 1:1 Set sample rate 192000, clock 40
[49672.696512] usb 3-3: 2:1: add audio endpoint 0x88
[49672.696539] usb 3-3: Creating new data endpoint #88
[49672.696803] usb 3-3: 2:1 Set sample rate 192000, clock 40
[49672.700437] usb 3-3: [10] FU [PCM Playback Switch] ch = 2, val = 0/1/1
[49672.700454] usb 3-3: [10] FU [PCM Playback Switch] ch = 1, val = 0/1/1
[49672.703760] usb 3-3: [10] FU [PCM Playback Volume] ch = 2, val = -32512/0/256
[49672.707047] usb 3-3: [10] FU [PCM Playback Volume] ch = 1, val = -32512/0/256
[49672.707540] usb 3-3: [11] FU [Mic Capture Switch] ch = 2, val = 0/1/1
[49672.707562] usb 3-3: [11] FU [Mic Capture Switch] ch = 1, val = 0/1/1
[49672.710665] usb 3-3: [11] FU [Mic Capture Volume] ch = 2, val = -32512/0/256
[49672.714037] usb 3-3: [11] FU [Mic Capture Volume] ch = 1, val = -32512/0/256
[49672.862329] usb 3-3: Open EP 0x88, iface=2:1, idx=0
[49672.862341] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49672.862349] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49672.862668] usb 3-3: 2:1 Set sample rate 48000, clock 40
[49672.865988] usb 3-3: Setting params for data EP 0x88, pipe 0x41680
[49672.866010] usb 3-3: Set up 12 URBS, ret=0
[49672.866016] usb 3-3: Setting usb interface 2:1 for EP 0x88
[49672.871524] usb 3-3: Closing EP 0x88 (count 1)
[49672.871531] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49672.872783] usb 3-3: EP 0x88 closed
[49672.873649] usb 3-3: Open EP 0x88, iface=2:1, idx=0
[49672.873657] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49672.873664] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49672.873937] usb 3-3: 2:1 Set sample rate 48000, clock 40
[49672.875980] usb 3-3: Setting params for data EP 0x88, pipe 0x41680
[49672.875992] usb 3-3: Set up 12 URBS, ret=0
[49672.875996] usb 3-3: Setting usb interface 2:1 for EP 0x88
[49672.877285] usb 3-3: Closing EP 0x88 (count 1)
[49672.877290] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49672.877669] usb 3-3: EP 0x88 closed
[49672.878685] usb 3-3: Open EP 0x8, iface=1:1, idx=0
[49672.878695] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49672.878703] usb 3-3: Open EP 0x84, iface=1:1, idx=1
[49672.878828] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49672.878838] usb 3-3: Setting usb interface 1:0 for EP 0x8
[49672.878968] usb 3-3: 1:1 Set sample rate 48000, clock 40
[49672.880042] usb 3-3: Setting params for data EP 0x8, pipe 0x41600
[49672.880062] usb 3-3: Set up 12 URBS, ret=0
[49672.880068] usb 3-3: Setting usb interface 1:1 for EP 0x8
[49672.880509] usb 3-3: Setting params for sync EP 0x84, pipe 0x21680
[49672.880517] usb 3-3: Set up 4 URBS, ret=0
[49672.883405] usb 3-3: Open EP 0x88, iface=2:1, idx=0
[49672.883414] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49672.883421] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49672.883605] usb 3-3: 2:1 Set sample rate 48000, clock 40
[49673.098932] usb 3-3: Setting params for data EP 0x88, pipe 0x41680
[49673.098958] usb 3-3: Set up 12 URBS, ret=0
[49673.098966] usb 3-3: Setting usb interface 2:1 for EP 0x88
[49673.099360] usb 3-3: Closing EP 0x88 (count 1)
[49673.099368] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.099743] usb 3-3: EP 0x88 closed
[49673.101201] usb 3-3: Open EP 0x88, iface=2:1, idx=0
[49673.101215] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49673.101227] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.101383] usb 3-3: 2:1 Set sample rate 48000, clock 40
[49673.102494] usb 3-3: Setting params for data EP 0x88, pipe 0x41680
[49673.102505] usb 3-3: Set up 12 URBS, ret=0
[49673.102508] usb 3-3: Setting usb interface 2:1 for EP 0x88
[49673.102892] usb 3-3: Closing EP 0x8 (count 1)
[49673.102899] usb 3-3: EP 0x8 closed
[49673.102903] usb 3-3: Closing EP 0x84 (count 1)
[49673.102907] usb 3-3: Setting usb interface 1:0 for EP 0x84
[49673.103270] usb 3-3: EP 0x84 closed
[49673.103325] usb 3-3: Closing EP 0x88 (count 1)
[49673.103330] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.103581] usb 3-3: EP 0x88 closed
[49673.117689] usb 3-3: Open EP 0x8, iface=1:1, idx=0
[49673.117709] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49673.117716] usb 3-3: Open EP 0x84, iface=1:1, idx=1
[49673.117722] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49673.117728] usb 3-3: Setting usb interface 1:0 for EP 0x8
[49673.117873] usb 3-3: 1:1 Set sample rate 48000, clock 40
[49673.121046] usb 3-3: Setting params for data EP 0x8, pipe 0x41600
[49673.121067] usb 3-3: Set up 12 URBS, ret=0
[49673.121074] usb 3-3: Setting usb interface 1:1 for EP 0x8
[49673.121433] usb 3-3: Setting params for sync EP 0x84, pipe 0x21680
[49673.121443] usb 3-3: Set up 4 URBS, ret=0
[49673.122892] usb 3-3: Open EP 0x88, iface=2:1, idx=0
[49673.122903] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49673.122913] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.123054] usb 3-3: 2:1 Set sample rate 48000, clock 40
[49673.124177] usb 3-3: Setting params for data EP 0x88, pipe 0x41680
[49673.124189] usb 3-3: Set up 12 URBS, ret=0
[49673.124192] usb 3-3: Setting usb interface 2:1 for EP 0x88
[49673.124503] usb 3-3: Closing EP 0x88 (count 1)
[49673.124508] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.124873] usb 3-3: EP 0x88 closed
[49673.125726] usb 3-3: Open EP 0x88, iface=2:1, idx=0
[49673.125733] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=9600, periods=4, implicit_fb=0
[49673.125739] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.125872] usb 3-3: 2:1 Set sample rate 48000, clock 40
[49673.126932] usb 3-3: Setting params for data EP 0x88, pipe 0x41680
[49673.126947] usb 3-3: Set up 12 URBS, ret=0
[49673.126952] usb 3-3: Setting usb interface 2:1 for EP 0x88
[49673.127204] usb 3-3: Closing EP 0x8 (count 1)
[49673.127208] usb 3-3: EP 0x8 closed
[49673.127210] usb 3-3: Closing EP 0x84 (count 1)
[49673.127212] usb 3-3: Setting usb interface 1:0 for EP 0x84
[49673.127647] usb 3-3: EP 0x84 closed
[49673.127724] usb 3-3: Closing EP 0x88 (count 1)
[49673.127730] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.128017] usb 3-3: EP 0x88 closed
[49673.141142] usb 3-3: Open EP 0x8, iface=1:1, idx=0
[49673.141154] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=384000, periods=2, implicit_fb=0
[49673.141161] usb 3-3: Open EP 0x84, iface=1:1, idx=1
[49673.141168] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=384000, periods=2, implicit_fb=0
[49673.141174] usb 3-3: Setting usb interface 1:0 for EP 0x8
[49673.141334] usb 3-3: 1:1 Set sample rate 48000, clock 40
[49673.142388] usb 3-3: Setting params for data EP 0x8, pipe 0x41600
[49673.142399] usb 3-3: Set up 12 URBS, ret=0
[49673.142402] usb 3-3: Setting usb interface 1:1 for EP 0x8
[49673.142677] usb 3-3: Setting params for sync EP 0x84, pipe 0x21680
[49673.142682] usb 3-3: Set up 4 URBS, ret=0
[49673.144794] usb 3-3: Starting data EP 0x8 (running 0)
[49673.144922] usb 3-3: 12 URBs submitted for EP 0x8
[49673.144928] usb 3-3: Starting sync EP 0x84 (running 0)
[49673.144952] usb 3-3: 4 URBs submitted for EP 0x84
[49673.144957] usb 3-3: 1:1 Start Playback PCM
[49673.147134] usb 3-3: Open EP 0x88, iface=2:1, idx=0
[49673.147146] usb 3-3:   channels=2, rate=48000, format=S32_LE, period_bytes=384000, periods=2, implicit_fb=0
[49673.147154] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49673.147303] usb 3-3: 2:1 Set sample rate 48000, clock 40
[49673.149667] usb 3-3: Setting params for data EP 0x88, pipe 0x41680
[49673.149753] usb 3-3: Set up 12 URBS, ret=0
[49673.149759] usb 3-3: Setting usb interface 2:1 for EP 0x88
[49673.152046] usb 3-3: Starting data EP 0x88 (running 0)
[49673.152132] usb 3-3: 12 URBs submitted for EP 0x88
[49673.152140] usb 3-3: 2:1 Start Capture PCM
[49678.149591] usb 3-3: Stopping sync EP 0x84 (running 1)
[49678.149611] usb 3-3: Stopping data EP 0x8 (running 1)
[49678.149646] usb 3-3: 1:1 Stop Playback PCM
[49678.149723] usb 3-3: Closing EP 0x8 (count 1)
[49678.149726] usb 3-3: EP 0x8 closed
[49678.149728] usb 3-3: Closing EP 0x84 (count 1)
[49678.149730] usb 3-3: Setting usb interface 1:0 for EP 0x84
[49678.150382] usb 3-3: EP 0x84 closed
[49678.152669] usb 3-3: Stopping data EP 0x88 (running 1)
[49678.152730] usb 3-3: 2:1 Stop Capture PCM
[49678.154511] usb 3-3: Closing EP 0x88 (count 1)
[49678.154530] usb 3-3: Setting usb interface 2:0 for EP 0x88
[49678.154870] usb 3-3: EP 0x88 closed