Hi All, I have a Numark Scratch mixer which I would like to use on Linux with Mixxx. The mixer should be class compliant but there is an issue and the Audio interface does not work. I hope to get your help in getting this fixed in the kernel. I'm on fedora 49 running kernel 6.9.5-200 Here's some info, I have found: $ dmesg [ 74.473642] usb 1-3: new high-speed USB device number 5 using xhci_hcd [ 74.600370] usb 1-3: language id specifier not provided by device, defaulting to English [ 74.600541] usb 1-3: New USB device found, idVendor=15e4, idProduct=0052, bcdDevice= 0.00 [ 74.600556] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 74.600566] usb 1-3: Product: Numark Scratch [ 74.600574] usb 1-3: Manufacturer: Numark [ 74.600580] usb 1-3: SerialNumber: N31911167105329 [ 74.604272] usb 1-3: Quirk or no altset; falling back to MIDI 1.0 [ 74.606706] usb 1-3: 3:1 : bogus bTerminalLink 1 [ 74.606802] usb 1-3: 4:1 : bogus bTerminalLink 4 [ 156.432125] usb 1-3: USB disconnect, device number 5 $ amidi -l Dir Device Name IO hw:0,0,0 Numark Scratch MIDI 1 $ aplay -l **** List of PLAYBACK Hardware Devices **** card 1: PCH [HDA Intel PCH], device 0: CX20753/4 Analog [CX20753/4 Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2] $ lsusb -v Bus 001 Device 045: ID 15e4:0052 Numark Numark Scratch Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 239 Miscellaneous Device bDeviceSubClass 2 [unknown] bDeviceProtocol 1 Interface Association bMaxPacketSize0 64 idVendor 0x15e4 Numark idProduct 0x0052 Numark Scratch bcdDevice 0.00 iManufacturer 1 Numark iProduct 2 Numark Scratch iSerial 3 N31911167105329 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 0x0164 bNumInterfaces 5 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xc0 Self Powered MaxPower 0mA Interface Association: bLength 8 bDescriptorType 11 bFirstInterface 0 bInterfaceCount 2 bFunctionClass 1 Audio bFunctionSubClass 0 [unknown] bFunctionProtocol 0 iFunction 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 1 Control Device bInterfaceProtocol 0 iInterface 2 AudioControl Interface Descriptor: bLength 9 bDescriptorType 36 bDescriptorSubtype 1 (HEADER) bcdADC 1.00 wTotalLength 0x0009 bInCollection 1 baInterfaceNr(0) 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 1 Audio bInterfaceSubClass 3 MIDI Streaming bInterfaceProtocol 0 iInterface 2 MIDIStreaming Interface Descriptor: bLength 7 bDescriptorType 36 bDescriptorSubtype 1 (HEADER) bcdADC 1.00 wTotalLength 0x0032 MIDIStreaming Interface Descriptor: bLength 6 bDescriptorType 36 bDescriptorSubtype 2 (MIDI_IN_JACK) bJackType 1 Embedded bJackID 1 iJack 0 MIDIStreaming Interface Descriptor: bLength 9 bDescriptorType 36 bDescriptorSubtype 3 (MIDI_OUT_JACK) bJackType 1 Embedded bJackID 2 bNrInputPins 1 baSourceID( 0) 1 BaSourcePin( 0) 1 iJack 0 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x04 EP 4 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 bRefresh 0 bSynchAddress 0 MIDIStreaming Endpoint Descriptor: bLength 5 bDescriptorType 37 bDescriptorSubtype 1 (Invalid) bNumEmbMIDIJack 1 baAssocJackID( 0) 1 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0200 1x 512 bytes bInterval 0 bRefresh 0 bSynchAddress 0 MIDIStreaming Endpoint Descriptor: bLength 5 bDescriptorType 37 bDescriptorSubtype 1 (Invalid) bNumEmbMIDIJack 1 baAssocJackID( 0) 2 Interface Association: bLength 8 bDescriptorType 11 bFirstInterface 2 bInterfaceCount 3 bFunctionClass 1 Audio bFunctionSubClass 0 [unknown] bFunctionProtocol 32 iFunction 2 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 1 Control Device bInterfaceProtocol 32 iInterface 2 AudioControl Interface Descriptor: bLength 9 bDescriptorType 36 bDescriptorSubtype 1 (HEADER) bcdADC 2.00 bCategory 8 wTotalLength 0x0087 bmControls 0x00 AudioControl Interface Descriptor: bLength 8 bDescriptorType 36 bDescriptorSubtype 10 (CLOCK_SOURCE) bClockID 5 bmAttributes 1 Internal fixed clock bmControls 0x05 Clock Frequency Control (read-only) Clock Validity Control (read-only) bAssocTerminal 0 iClockSource 2 AudioControl Interface Descriptor: bLength 17 bDescriptorType 36 bDescriptorSubtype 2 (INPUT_TERMINAL) bTerminalID 1 wTerminalType 0x0101 USB Streaming bAssocTerminal 0 bCSourceID 5 bNrChannels 4 bmChannelConfig 0x00000000 iChannelNames 4 bmControls 0x0000 iTerminal 2 AudioControl Interface Descriptor: bLength 26 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 6 bSourceID 1 bmaControls(0) 0x00000000 bmaControls(1) 0x00000000 bmaControls(2) 0x00000000 bmaControls(3) 0x00000000 bmaControls(4) 0x00000000 iFeature 0 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 3 (OUTPUT_TERMINAL) bTerminalID 2 wTerminalType 0x0301 Speaker bAssocTerminal 0 bSourceID 6 bCSourceID 5 bmControls 0x0000 iTerminal 2 AudioControl Interface Descriptor: bLength 17 bDescriptorType 36 bDescriptorSubtype 2 (INPUT_TERMINAL) bTerminalID 3 wTerminalType 0x0201 Microphone bAssocTerminal 0 bCSourceID 5 bNrChannels 6 bmChannelConfig 0x00000000 iChannelNames 8 bmControls 0x0000 iTerminal 2 AudioControl Interface Descriptor: bLength 34 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 7 bSourceID 3 bmaControls(0) 0x00000000 bmaControls(1) 0x00000000 bmaControls(2) 0x00000000 bmaControls(3) 0x00000000 bmaControls(4) 0x00000000 bmaControls(5) 0x00000000 bmaControls(6) 0x00000000 iFeature 2 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 3 (OUTPUT_TERMINAL) bTerminalID 4 wTerminalType 0x0101 USB Streaming bAssocTerminal 0 bSourceID 7 bCSourceID 5 bmControls 0x0000 iTerminal 2 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 3 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 32 iInterface 2 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 3 bAlternateSetting 1 bNumEndpoints 1 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 32 iInterface 2 AudioStreaming Interface Descriptor: bLength 16 bDescriptorType 36 bDescriptorSubtype 1 (AS_GENERAL) bTerminalLink 1 bmControls 0x00 bFormatType 1 bmFormats 0x00000001 PCM bNrChannels 4 bmChannelConfig 0x00000000 iChannelNames 4 AudioStreaming Interface Descriptor: bLength 6 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bSubslotSize 4 bBitResolution 24 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x05 EP 5 OUT bmAttributes 5 Transfer Type Isochronous Synch Type Asynchronous Usage Type Data wMaxPacketSize 0x0070 1x 112 bytes bInterval 1 AudioStreaming Endpoint Descriptor: bLength 8 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x00 bmControls 0x00 bLockDelayUnits 0 Undefined wLockDelay 0x0000 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 4 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 32 iInterface 2 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 4 bAlternateSetting 1 bNumEndpoints 1 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 32 iInterface 2 AudioStreaming Interface Descriptor: bLength 16 bDescriptorType 36 bDescriptorSubtype 1 (AS_GENERAL) bTerminalLink 4 bmControls 0x00 bFormatType 1 bmFormats 0x00000001 PCM bNrChannels 6 bmChannelConfig 0x00000000 iChannelNames 8 AudioStreaming Interface Descriptor: bLength 6 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bSubslotSize 4 bBitResolution 24 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x85 EP 5 IN bmAttributes 37 Transfer Type Isochronous Synch Type Asynchronous Usage Type Implicit feedback Data wMaxPacketSize 0x00a8 1x 168 bytes bInterval 1 AudioStreaming Endpoint Descriptor: bLength 8 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x00 bmControls 0x00 bLockDelayUnits 0 Undefined wLockDelay 0x0000 Regards Al