This device has a broken vendor-specific altsetting for interface 1, where endpoint 0x85 is declared as an isochronous endpoint despite being used by interface 2 for audio capture.

Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 239 Miscellaneous Device bDeviceSubClass 2 bDeviceProtocol 1 Interface Association bMaxPacketSize0 64 idVendor 0x0926 idProduct 0x0202 bcdDevice 1.00 iManufacturer 1 Sound Devices iProduct 2 USBPre2 iSerial 3 [...] bNumConfigurations 1

[...]

Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 3 bNumEndpoints 2 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x85 EP 5 IN bmAttributes 5 Transfer Type Isochronous Synch Type Asynchronous Usage Type Data wMaxPacketSize 0x0126 1x 294 bytes bInterval 1

[...]

Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 1 bNumEndpoints 1 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 0 iInterface 0 AudioStreaming Interface Descriptor: bLength 7 bDescriptorType 36 bDescriptorSubtype 1 (AS_GENERAL) bTerminalLink 4 bDelay 1 frames wFormatTag 0x0001 PCM AudioStreaming Interface Descriptor: bLength 26 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 2 bSubframeSize 2 bBitResolution 16 bSamFreqType 6 Discrete tSamFreq[ 0] 8000 tSamFreq[ 1] 16000 tSamFreq[ 2] 24000 tSamFreq[ 3] 32000 tSamFreq[ 4] 44100 tSamFreq[ 5] 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x85 EP 5 IN bmAttributes 5 Transfer Type Isochronous Synch Type Asynchronous Usage Type Data wMaxPacketSize 0x0126 1x 294 bytes bInterval 4 bRefresh 0 bSynchAddress 0 AudioStreaming Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 2 Decoded PCM samples wLockDelay 0x0000

Since commit 3e4f8e21c4f2 ("USB: core: fix check for duplicate endpoints") USB core ignores any duplicate endpoints found during descriptor parsing, but in this case we need to ignore the first instance in order to avoid breaking the audio capture interface.

Fixes: 3e4f8e21c4f2 ("USB: core: fix check for duplicate endpoints") Cc: stable stable@vger.kernel.org Reported-by: edes edes@gmx.net Tested-by: edes edes@gmx.net Link: https://lore.kernel.org/r/20200201105829.5682c887@acme7.acmenet Signed-off-by: Johan Hovold johan@kernel.org --- drivers/usb/core/quirks.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c index 56c8dffaf5f5..f27468966a3d 100644 --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -354,6 +354,10 @@ static const struct usb_device_id usb_quirk_list[] = { { USB_DEVICE(0x0904, 0x6103), .driver_info = USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL },

+ /* Sound Devices USBPre2 */ + { USB_DEVICE(0x0926, 0x0202), .driver_info = + USB_QUIRK_ENDPOINT_BLACKLIST }, + /* Keytouch QWERTY Panel keyboard */ { USB_DEVICE(0x0926, 0x3333), .driver_info = USB_QUIRK_CONFIG_INTF_STRINGS }, @@ -479,6 +483,7 @@ static const struct usb_device_id usb_amd_resume_quirk_list[] = { * Matched for devices with USB_QUIRK_ENDPOINT_BLACKLIST. */ static const struct usb_device_id usb_endpoint_blacklist[] = { + { USB_DEVICE_INTERFACE_NUMBER(0x0926, 0x0202, 1), .driver_info = 0x85 }, { } };