I tried to use Skype (4.1) with Polycom Communicator C100S. Audio output works fine but mic seems to be dead, although it is set to capture and volume is even max. Dmesg tells the following two kinds of "cannot get freq at ep ..." messages while trying to use it.

Linux is 3.12-rc2 but I saw the same behaviour a couple releases ago when I first tried it.

I am not subscribed to alsa-devel, please CC in replies.

dmesg

[117273.437015] usb 1-1.2.3: new full-speed USB device number 9 using ehci-pci [117273.901033] usb 1-1.2.3: New USB device found, idVendor=095d, idProduct=0005 [117273.901036] usb 1-1.2.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [117273.901037] usb 1-1.2.3: Product: Polycom Communicator [117273.901038] usb 1-1.2.3: Manufacturer: Polycom,Inc. [117273.901039] usb 1-1.2.3: SerialNumber: L80646021E21 [117273.962134] hid-generic 0003:095D:0005.0005: hiddev0,hidraw3: USB HID v1.00 Device [Polycom,Inc. Polycom Communicator] on usb-0000:00:1a.0-1.2.3/input3 [117273.974525] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117273.978540] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117274.019749] usbcore: registered new interface driver snd-usb-audio [117380.633919] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117380.636540] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117383.587846] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117383.619463] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117383.639484] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117383.671451] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117383.697219] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117383.699840] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117385.663752] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117385.666495] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117386.090400] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117386.122894] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117386.143015] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117386.174880] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117386.200626] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117386.203252] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117392.696024] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117392.698650] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117395.407411] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117395.410160] ALSA sound/usb/clock.c:309 9:1:1: cannot get freq at ep 0x82 [117449.635703] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1 [117449.638451] ALSA sound/usb/clock.c:309 9:2:1: cannot get freq at ep 0x1

lsusb -v

Bus 001 Device 008: ID 095d:0005 Polycom, Inc. Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x095d Polycom, Inc. idProduct 0x0005 bcdDevice 1.00 iManufacturer 1 iProduct 2 iSerial 3 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 231 bNumInterfaces 4 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 500mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 1 Control Device bInterfaceProtocol 0 iInterface 0 AudioControl Interface Descriptor: bLength 10 bDescriptorType 36 bDescriptorSubtype 1 (HEADER) bcdADC 1.00 wTotalLength 83 bInCollection 2 baInterfaceNr( 0) 2 baInterfaceNr( 1) 1 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 2 (INPUT_TERMINAL) bTerminalID 1 wTerminalType 0x0201 Microphone bAssocTerminal 0 bNrChannels 2 wChannelConfig 0x0003 Left Front (L) Right Front (R) iChannelNames 0 iTerminal 0 AudioControl Interface Descriptor: bLength 10 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 2 bSourceID 1 bControlSize 1 bmaControls( 0) 0x03 Mute Control Volume Control bmaControls( 1) 0x00 bmaControls( 2) 0x00 iFeature 0 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 4 (MIXER_UNIT) bUnitID 3 bNrInPins 1 baSourceID( 0) 2 bNrChannels 2 wChannelConfig 0x0003 Left Front (L) Right Front (R) iChannelNames 0 bmControls 0x00 iMixer 0 AudioControl Interface Descriptor: bLength 9 bDescriptorType 36 bDescriptorSubtype 3 (OUTPUT_TERMINAL) bTerminalID 4 wTerminalType 0x0101 USB Streaming bAssocTerminal 0 bSourceID 3 iTerminal 0 AudioControl Interface Descriptor: bLength 12 bDescriptorType 36 bDescriptorSubtype 2 (INPUT_TERMINAL) bTerminalID 5 wTerminalType 0x0101 USB Streaming bAssocTerminal 0 bNrChannels 2 wChannelConfig 0x0003 Left Front (L) Right Front (R) iChannelNames 0 iTerminal 0 AudioControl Interface Descriptor: bLength 10 bDescriptorType 36 bDescriptorSubtype 6 (FEATURE_UNIT) bUnitID 6 bSourceID 5 bControlSize 1 bmaControls( 0) 0x03 Mute Control Volume Control bmaControls( 1) 0x00 bmaControls( 2) 0x00 iFeature 0 AudioControl Interface Descriptor: bLength 9 bDescriptorType 36 bDescriptorSubtype 3 (OUTPUT_TERMINAL) bTerminalID 7 wTerminalType 0x0301 Speaker bAssocTerminal 0 bSourceID 6 iTerminal 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 0 iInterface 0 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 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 1 PCM AudioStreaming Interface Descriptor: bLength 11 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 2 bSubframeSize 2 bBitResolution 16 bSamFreqType 1 Discrete tSamFreq[ 0] 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 13 Transfer Type Isochronous Synch Type Synchronous Usage Type Data wMaxPacketSize 0x00c0 1x 192 bytes bInterval 1 bRefresh 0 bSynchAddress 0 AudioControl Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 0 Undefined wLockDelay 0 Undefined Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 2 bAlternateSetting 0 bNumEndpoints 0 bInterfaceClass 1 Audio bInterfaceSubClass 2 Streaming bInterfaceProtocol 0 iInterface 0 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 5 bDelay 1 frames wFormatTag 1 PCM AudioStreaming Interface Descriptor: bLength 11 bDescriptorType 36 bDescriptorSubtype 2 (FORMAT_TYPE) bFormatType 1 (FORMAT_TYPE_I) bNrChannels 2 bSubframeSize 2 bBitResolution 16 bSamFreqType 1 Discrete tSamFreq[ 0] 48000 Endpoint Descriptor: bLength 9 bDescriptorType 5 bEndpointAddress 0x01 EP 1 OUT bmAttributes 13 Transfer Type Isochronous Synch Type Synchronous Usage Type Data wMaxPacketSize 0x00c0 1x 192 bytes bInterval 1 bRefresh 0 bSynchAddress 0 AudioControl Endpoint Descriptor: bLength 7 bDescriptorType 37 bDescriptorSubtype 1 (EP_GENERAL) bmAttributes 0x01 Sampling Frequency bLockDelayUnits 0 Undefined wLockDelay 0 Undefined Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 3 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Device bInterfaceSubClass 0 No Subclass bInterfaceProtocol 0 None iInterface 0 HID Device Descriptor: bLength 9 bDescriptorType 33 bcdHID 1.00 bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report wDescriptorLength 52 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0008 1x 8 bytes bInterval 10