{"action":"created","issue":{"url":"https://api.github.com/repos/raspberrypi/linux/issues/1051","labels_url":"https://api.github.com/repos/raspberrypi/linux/issues/1051/labels{/name}","comments_url":"https://api.github.com/repos/raspberrypi/linux/issues/1051/comments","events_url":"https://api.github.com/repos/raspberrypi/linux/issues/1051/events","html_url":"https://github.com/raspberrypi/linux/issues/1051","id":94079611,"number":1051,"title":"Changing SPI frequency/speed in fbtft driver causes usb based audio to play at the wrong speed","user":{"login":"pssc","id":1763553,"avatar_url":"https://avatars.githubusercontent.com/u/1763553?v=3","gravatar_id":"","url":"https://api.github.com/users/pssc","html_url":"https://github.com/pssc","followers_url":"https://api.github.com/users/pssc/followers","following_url":"https://api.github.com/users/pssc/following{/other_user}","gists_url":"https://api.github.com/users/pssc/gists{/gist_id}","starred_url":"https://api.github.com/users/pssc/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pssc/subscriptions","organizations_url":"https://api.github.com/users/pssc/orgs","repos_url":"https://api.github.com/users/pssc/repos","events_url":"https://api.github.com/users/pssc/events{/privacy}","received_events_url":"https://api.github.com/users/pssc/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":31,"created_at":"2015-07-09T15:29:57Z","updated_at":"2015-08-17T15:46:47Z","closed_at":null,"body":"I am seeing this on multiple pis of differing types and kernel versions setting dtparam to anything other than 25Mhz causes issues.\r\n\r\n```\r\nconfig.txt\r\ndisable_audio_dither=1\r\n\r\ndtdebug=1\r\ndtoverlay=pitft28-resistive-overlay\r\ndtparam=fps=6\r\ndtparam=speed=25000000\r\n#dtparam=speed=32000000\r\n#dtparam=speed=42000000\r\ndtoverlay=pitft28-switches\r\n#dtparam=debounce=50\r\n```\r\n\r\n```\r\nLinux raspberrypi 3.18.14+ #794 PREEMPT Sun Jun 7 12:02:04 BST 2015 armv6l GNU/Linux\r\n```\r\n\r\n```\r\nroot@raspberrypi:/home/pi# aplay -l\r\n**** List of PLAYBACK Hardware Devices ****\r\ncard 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]\r\n  Subdevices: 7/8\r\n  Subdevice #0: subdevice #0\r\n  Subdevice #1: subdevice #1\r\n  Subdevice #2: subdevice #2\r\n  Subdevice #3: subdevice #3\r\n  Subdevice #4: subdevice #4\r\n  Subdevice #5: subdevice #5\r\n  Subdevice #6: subdevice #6\r\n  Subdevice #7: subdevice #7\r\ncard 0: ALSA [bcm2835 ALSA], device 1: bcm2835 ALSA [bcm2835 IEC958/HDMI]\r\n  Subdevices: 1/1\r\n  Subdevice #0: subdevice #0\r\ncard 1: CODEC [USB Audio CODEC], device 0: USB Audio [USB Audio]\r\n  Subdevices: 0/1\r\n  Subdevice #0: subdevice #0\r\n```\r\n```\r\n\r\nBus 001 Device 002: ID 0424:9512 Standard Microsystems Corp. \r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               2.00\r\n  bDeviceClass            9 Hub\r\n  bDeviceSubClass         0 Unused\r\n  bDeviceProtocol         2 TT per port\r\n  bMaxPacketSize0        64\r\n  idVendor           0x0424 Standard Microsystems Corp.\r\n  idProduct          0x9512 \r\n  bcdDevice            2.00\r\n  iManufacturer           0 \r\n  iProduct                0 \r\n  iSerial                 0 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength           41\r\n    bNumInterfaces          1\r\n    bConfigurationValue     1\r\n    iConfiguration          0 \r\n    bmAttributes         0xe0\r\n      Self Powered\r\n      Remote Wakeup\r\n    MaxPower                2mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         9 Hub\r\n      bInterfaceSubClass      0 Unused\r\n      bInterfaceProtocol      1 Single TT\r\n      iInterface              0 \r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0001  1x 1 bytes\r\n        bInterval              12\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       1\r\n      bNumEndpoints           1\r\n      bInterfaceClass         9 Hub\r\n      bInterfaceSubClass      0 Unused\r\n      bInterfaceProtocol      2 TT per port\r\n      iInterface              0 \r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0001  1x 1 bytes\r\n        bInterval              12\r\n\r\nBus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub\r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               2.00\r\n  bDeviceClass            9 Hub\r\n  bDeviceSubClass         0 Unused\r\n  bDeviceProtocol         1 Single TT\r\n  bMaxPacketSize0        64\r\n  idVendor           0x1d6b Linux Foundation\r\n  idProduct          0x0002 2.0 root hub\r\n  bcdDevice            3.18\r\n  iManufacturer           3 \r\n  iProduct                2 \r\n  iSerial                 1 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength           25\r\n    bNumInterfaces          1\r\n    bConfigurationValue     1\r\n    iConfiguration          0 \r\n    bmAttributes         0xe0\r\n      Self Powered\r\n      Remote Wakeup\r\n    MaxPower                0mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         9 Hub\r\n      bInterfaceSubClass      0 Unused\r\n      bInterfaceProtocol      0 Full speed (or root) hub\r\n      iInterface              0 \r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0004  1x 4 bytes\r\n        bInterval              12\r\n\r\nBus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. \r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               2.00\r\n  bDeviceClass          255 Vendor Specific Class\r\n  bDeviceSubClass         0 \r\n  bDeviceProtocol         1 \r\n  bMaxPacketSize0        64\r\n  idVendor           0x0424 Standard Microsystems Corp.\r\n  idProduct          0xec00 \r\n  bcdDevice            2.00\r\n  iManufacturer           0 \r\n  iProduct                0 \r\n  iSerial                 0 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength           39\r\n    bNumInterfaces          1\r\n    bConfigurationValue     1\r\n    iConfiguration          0 \r\n    bmAttributes         0xe0\r\n      Self Powered\r\n      Remote Wakeup\r\n    MaxPower                2mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           3\r\n      bInterfaceClass       255 Vendor Specific Class\r\n      bInterfaceSubClass      0 \r\n      bInterfaceProtocol    255 \r\n      iInterface              0 \r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            2\r\n          Transfer Type            Bulk\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0200  1x 512 bytes\r\n        bInterval               0\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            2\r\n          Transfer Type            Bulk\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0200  1x 512 bytes\r\n        bInterval               0\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x83  EP 3 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0010  1x 16 bytes\r\n        bInterval               4\r\n\r\nBus 001 Device 004: ID 7392:7811 Edimax Technology Co., Ltd EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS]\r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               2.00\r\n  bDeviceClass            0 (Defined at Interface level)\r\n  bDeviceSubClass         0 \r\n  bDeviceProtocol         0 \r\n  bMaxPacketSize0        64\r\n  idVendor           0x7392 Edimax Technology Co., Ltd\r\n  idProduct          0x7811 EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS]\r\n  bcdDevice            2.00\r\n  iManufacturer           1 \r\n  iProduct                2 \r\n  iSerial                 3 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength           46\r\n    bNumInterfaces          1\r\n    bConfigurationValue     1\r\n    iConfiguration          0 \r\n    bmAttributes         0x80\r\n      (Bus Powered)\r\n    MaxPower              500mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           4\r\n      bInterfaceClass       255 Vendor Specific Class\r\n      bInterfaceSubClass    255 Vendor Specific Subclass\r\n      bInterfaceProtocol    255 Vendor Specific Protocol\r\n      iInterface              0 \r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            2\r\n          Transfer Type            Bulk\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0200  1x 512 bytes\r\n        bInterval               0\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            2\r\n          Transfer Type            Bulk\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0200  1x 512 bytes\r\n        bInterval               0\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x03  EP 3 OUT\r\n        bmAttributes            2\r\n          Transfer Type            Bulk\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0200  1x 512 bytes\r\n        bInterval               0\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0040  1x 64 bytes\r\n        bInterval               1\r\n\r\nBus 001 Device 005: ID 1a40:0201 Terminus Technology Inc. FE 2.1 7-port Hub\r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               2.00\r\n  bDeviceClass            9 Hub\r\n  bDeviceSubClass         0 Unused\r\n  bDeviceProtocol         2 TT per port\r\n  bMaxPacketSize0        64\r\n  idVendor           0x1a40 Terminus Technology Inc.\r\n  idProduct          0x0201 FE 2.1 7-port Hub\r\n  bcdDevice            1.00\r\n  iManufacturer           0 \r\n  iProduct                1 \r\n  iSerial                 0 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength           41\r\n    bNumInterfaces          1\r\n    bConfigurationValue     1\r\n    iConfiguration          0 \r\n    bmAttributes         0xe0\r\n      Self Powered\r\n      Remote Wakeup\r\n    MaxPower              100mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         9 Hub\r\n      bInterfaceSubClass      0 Unused\r\n      bInterfaceProtocol      1 Single TT\r\n      iInterface              0 \r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0001  1x 1 bytes\r\n        bInterval              12\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       1\r\n      bNumEndpoints           1\r\n      bInterfaceClass         9 Hub\r\n      bInterfaceSubClass      0 Unused\r\n      bInterfaceProtocol      2 TT per port\r\n      iInterface              0 \r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0001  1x 1 bytes\r\n        bInterval              12\r\n\r\nBus 001 Device 006: ID 08bb:2902 Texas Instruments Japan PCM2902 Audio Codec\r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               1.10\r\n  bDeviceClass            0 (Defined at Interface level)\r\n  bDeviceSubClass         0 \r\n  bDeviceProtocol         0 \r\n  bMaxPacketSize0         8\r\n  idVendor           0x08bb Texas Instruments Japan\r\n  idProduct          0x2902 PCM2902 Audio Codec\r\n  bcdDevice            1.00\r\n  iManufacturer           1 \r\n  iProduct                2 \r\n  iSerial                 0 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength         1191\r\n    bNumInterfaces          4\r\n    bConfigurationValue     1\r\n    iConfiguration          0 \r\n    bmAttributes         0x80\r\n      (Bus Powered)\r\n    MaxPower              100mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           0\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      1 Control Device\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioControl Interface Descriptor:\r\n        bLength                10\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (HEADER)\r\n        bcdADC               1.00\r\n        wTotalLength           62\r\n        bInCollection           2\r\n        baInterfaceNr( 0)       1\r\n        baInterfaceNr( 1)       2\r\n      AudioControl Interface Descriptor:\r\n        bLength                12\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (INPUT_TERMINAL)\r\n        bTerminalID             1\r\n        wTerminalType      0x0101 USB Streaming\r\n        bAssocTerminal          0\r\n        bNrChannels             2\r\n        wChannelConfig     0x0003\r\n          Left Front (L)\r\n          Right Front (R)\r\n        iChannelNames           0 \r\n        iTerminal               0 \r\n      AudioControl Interface Descriptor:\r\n        bLength                 9\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      3 (OUTPUT_TERMINAL)\r\n        bTerminalID             2\r\n        wTerminalType      0x0301 Speaker\r\n        bAssocTerminal          0\r\n        bSourceID               3\r\n        iTerminal               0 \r\n      AudioControl Interface Descriptor:\r\n        bLength                10\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      6 (FEATURE_UNIT)\r\n        bUnitID                 3\r\n        bSourceID               1\r\n        bControlSize            1\r\n        bmaControls( 0)      0x01\r\n          Mute Control\r\n        bmaControls( 1)      0x02\r\n          Volume Control\r\n        bmaControls( 2)      0x02\r\n          Volume Control\r\n        iFeature                0 \r\n      AudioControl Interface Descriptor:\r\n        bLength                12\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (INPUT_TERMINAL)\r\n        bTerminalID             4\r\n        wTerminalType      0x0201 Microphone\r\n        bAssocTerminal          0\r\n        bNrChannels             2\r\n        wChannelConfig     0x0003\r\n          Left Front (L)\r\n          Right Front (R)\r\n        iChannelNames           0 \r\n        iTerminal               0 \r\n      AudioControl Interface Descriptor:\r\n        bLength                 9\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      3 (OUTPUT_TERMINAL)\r\n        bTerminalID             5\r\n        wTerminalType      0x0101 USB Streaming\r\n        bAssocTerminal          0\r\n        bSourceID               4\r\n        iTerminal               0 \r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       0\r\n      bNumEndpoints           0\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       1\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           1\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                17\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            3 Discrete\r\n        tSamFreq[ 0]        32000\r\n        tSamFreq[ 1]        44100\r\n        tSamFreq[ 2]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            9\r\n          Transfer Type            Isochronous\r\n          Synch Type               Adaptive\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x00c0  1x 192 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay            512 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       2\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           1\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                17\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            3 Discrete\r\n        tSamFreq[ 0]        32000\r\n        tSamFreq[ 1]        44100\r\n        tSamFreq[ 2]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            9\r\n          Transfer Type            Isochronous\r\n          Synch Type               Adaptive\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0060  1x 96 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay            512 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       3\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           1\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                17\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            3 Discrete\r\n        tSamFreq[ 0]        32000\r\n        tSamFreq[ 1]        44100\r\n        tSamFreq[ 2]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            9\r\n          Transfer Type            Isochronous\r\n          Synch Type               Adaptive\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0060  1x 96 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay            512 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       4\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           1\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                17\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            3 Discrete\r\n        tSamFreq[ 0]        32000\r\n        tSamFreq[ 1]        44100\r\n        tSamFreq[ 2]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            9\r\n          Transfer Type            Isochronous\r\n          Synch Type               Adaptive\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0030  1x 48 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay            512 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       5\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           1\r\n        bDelay                  0 frames\r\n        wFormatTag              2 PCM8\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                17\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            3 Discrete\r\n        tSamFreq[ 0]        32000\r\n        tSamFreq[ 1]        44100\r\n        tSamFreq[ 2]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            9\r\n          Transfer Type            Isochronous\r\n          Synch Type               Adaptive\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0060  1x 96 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay            512 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       6\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           1\r\n        bDelay                  0 frames\r\n        wFormatTag              2 PCM8\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                17\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            3 Discrete\r\n        tSamFreq[ 0]        32000\r\n        tSamFreq[ 1]        44100\r\n        tSamFreq[ 2]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x02  EP 2 OUT\r\n        bmAttributes            9\r\n          Transfer Type            Isochronous\r\n          Synch Type               Adaptive\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0030  1x 48 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay            512 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       0\r\n      bNumEndpoints           0\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       1\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x00c4  1x 196 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       2\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        48000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0062  1x 98 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       3\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        44100\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x00b4  1x 180 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       4\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        44100\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x005a  1x 90 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       5\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        32000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0084  1x 132 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       6\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        32000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0042  1x 66 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       7\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        22050\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x005c  1x 92 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       8\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        22050\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x002e  1x 46 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting       9\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        16000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0044  1x 68 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      10\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        16000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0022  1x 34 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      11\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        16000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0022  1x 34 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      12\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        16000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0011  1x 17 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      13\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]         8000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0012  1x 18 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      14\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]         8000\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes            5\r\n          Transfer Type            Isochronous\r\n          Synch Type               Asynchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0009  1x 9 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      15\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        11025\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes           13\r\n          Transfer Type            Isochronous\r\n          Synch Type               Synchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0030  1x 48 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      16\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           2\r\n        bBitResolution         16\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        11025\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes           13\r\n          Transfer Type            Isochronous\r\n          Synch Type               Synchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0018  1x 24 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      17\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             2\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        11025\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes           13\r\n          Transfer Type            Isochronous\r\n          Synch Type               Synchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0018  1x 24 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        2\r\n      bAlternateSetting      18\r\n      bNumEndpoints           1\r\n      bInterfaceClass         1 Audio\r\n      bInterfaceSubClass      2 Streaming\r\n      bInterfaceProtocol      0 \r\n      iInterface              0 \r\n      AudioStreaming Interface Descriptor:\r\n        bLength                 7\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      1 (AS_GENERAL)\r\n        bTerminalLink           5\r\n        bDelay                  0 frames\r\n        wFormatTag              1 PCM\r\n      AudioStreaming Interface Descriptor:\r\n        bLength                11\r\n        bDescriptorType        36\r\n        bDescriptorSubtype      2 (FORMAT_TYPE)\r\n        bFormatType             1 (FORMAT_TYPE_I)\r\n        bNrChannels             1\r\n        bSubframeSize           1\r\n        bBitResolution          8\r\n        bSamFreqType            1 Discrete\r\n        tSamFreq[ 0]        11025\r\n      Endpoint Descriptor:\r\n        bLength                 9\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x84  EP 4 IN\r\n        bmAttributes           13\r\n          Transfer Type            Isochronous\r\n          Synch Type               Synchronous\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x000c  1x 12 bytes\r\n        bInterval               1\r\n        bRefresh                0\r\n        bSynchAddress           0\r\n        AudioControl Endpoint Descriptor:\r\n          bLength                 7\r\n          bDescriptorType        37\r\n          bDescriptorSubtype      1 (EP_GENERAL)\r\n          bmAttributes         0x00\r\n          bLockDelayUnits         2 Decoded PCM samples\r\n          wLockDelay              0 Decoded PCM samples\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        3\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         3 Human Interface Device\r\n      bInterfaceSubClass      0 No Subclass\r\n      bInterfaceProtocol      0 None\r\n      iInterface              0 \r\n        HID Device Descriptor:\r\n          bLength                 9\r\n          bDescriptorType        33\r\n          bcdHID               1.00\r\n          bCountryCode            0 Not supported\r\n          bNumDescriptors         1\r\n          bDescriptorType        34 Report\r\n          wDescriptorLength      31\r\n         Report Descriptors: \r\n           ** UNAVAILABLE **\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x85  EP 5 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0001  1x 1 bytes\r\n        bInterval              10\r\n\r\nBus 001 Device 007: ID 1d57:ad02 Xenta \r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               1.10\r\n  bDeviceClass            0 (Defined at Interface level)\r\n  bDeviceSubClass         0 \r\n  bDeviceProtocol         0 \r\n  bMaxPacketSize0         8\r\n  idVendor           0x1d57 Xenta\r\n  idProduct          0xad02 \r\n  bcdDevice            1.05\r\n  iManufacturer           0 \r\n  iProduct                0 \r\n  iSerial                 0 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength           59\r\n    bNumInterfaces          2\r\n    bConfigurationValue     1\r\n    iConfiguration          0 \r\n    bmAttributes         0xa0\r\n      (Bus Powered)\r\n      Remote Wakeup\r\n    MaxPower              100mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         3 Human Interface Device\r\n      bInterfaceSubClass      1 Boot Interface Subclass\r\n      bInterfaceProtocol      1 Keyboard\r\n      iInterface              0 \r\n        HID Device Descriptor:\r\n          bLength                 9\r\n          bDescriptorType        33\r\n          bcdHID               1.10\r\n          bCountryCode           33 US\r\n          bNumDescriptors         1\r\n          bDescriptorType        34 Report\r\n          wDescriptorLength     131\r\n         Report Descriptors: \r\n           ** UNAVAILABLE **\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0008  1x 8 bytes\r\n        bInterval              10\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         3 Human Interface Device\r\n      bInterfaceSubClass      1 Boot Interface Subclass\r\n      bInterfaceProtocol      2 Mouse\r\n      iInterface              0 \r\n        HID Device Descriptor:\r\n          bLength                 9\r\n          bDescriptorType        33\r\n          bcdHID               1.10\r\n          bCountryCode            0 Not supported\r\n          bNumDescriptors         1\r\n          bDescriptorType        34 Report\r\n          wDescriptorLength      77\r\n         Report Descriptors: \r\n           ** UNAVAILABLE **\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x82  EP 2 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0005  1x 5 bytes\r\n        bInterval              10\r\n\r\nBus 001 Device 008: ID 0dc6:3412 Precision Squared Technology Corp. \r\nDevice Descriptor:\r\n  bLength                18\r\n  bDescriptorType         1\r\n  bcdUSB               1.10\r\n  bDeviceClass            0 (Defined at Interface level)\r\n  bDeviceSubClass         0 \r\n  bDeviceProtocol         0 \r\n  bMaxPacketSize0         8\r\n  idVendor           0x0dc6 Precision Squared Technology Corp.\r\n  idProduct          0x3412 \r\n  bcdDevice            1.03\r\n  iManufacturer           0 \r\n  iProduct                2 \r\n  iSerial                 0 \r\n  bNumConfigurations      1\r\n  Configuration Descriptor:\r\n    bLength                 9\r\n    bDescriptorType         2\r\n    wTotalLength           59\r\n    bNumInterfaces          2\r\n    bConfigurationValue     1\r\n    iConfiguration          4 \r\n    bmAttributes         0xa0\r\n      (Bus Powered)\r\n      Remote Wakeup\r\n    MaxPower              100mA\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        0\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         3 Human Interface Device\r\n      bInterfaceSubClass      1 Boot Interface Subclass\r\n      bInterfaceProtocol      1 Keyboard\r\n      iInterface              5 \r\n        HID Device Descriptor:\r\n          bLength                 9\r\n          bDescriptorType        33\r\n          bcdHID               1.00\r\n          bCountryCode            0 Not supported\r\n          bNumDescriptors         1\r\n          bDescriptorType        34 Report\r\n          wDescriptorLength      65\r\n         Report Descriptors: \r\n           ** UNAVAILABLE **\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x81  EP 1 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0008  1x 8 bytes\r\n        bInterval              10\r\n    Interface Descriptor:\r\n      bLength                 9\r\n      bDescriptorType         4\r\n      bInterfaceNumber        1\r\n      bAlternateSetting       0\r\n      bNumEndpoints           1\r\n      bInterfaceClass         3 Human Interface Device\r\n      bInterfaceSubClass      1 Boot Interface Subclass\r\n      bInterfaceProtocol      2 Mouse\r\n      iInterface              6 \r\n        HID Device Descriptor:\r\n          bLength                 9\r\n          bDescriptorType        33\r\n          bcdHID               1.00\r\n          bCountryCode            0 Not supported\r\n          bNumDescriptors         1\r\n          bDescriptorType        34 Report\r\n          wDescriptorLength      52\r\n         Report Descriptors: \r\n           ** UNAVAILABLE **\r\n      Endpoint Descriptor:\r\n        bLength                 7\r\n        bDescriptorType         5\r\n        bEndpointAddress     0x82  EP 2 IN\r\n        bmAttributes            3\r\n          Transfer Type            Interrupt\r\n          Synch Type               None\r\n          Usage Type               Data\r\n        wMaxPacketSize     0x0008  1x 8 bytes\r\n        bInterval              10\r\n```\r\n"},"comment":{"url":"https://api.github.com/repos/raspberrypi/linux/issues/comments/131869498","html_url":"https://github.com/raspberrypi/linux/issues/1051#issuecomment-131869498","issue_url":"https://api.github.com/repos/raspberrypi/linux/issues/1051","id":131869498,"user":{"login":"P33M","id":2474547,"avatar_url":"https://avatars.githubusercontent.com/u/2474547?v=3","gravatar_id":"","url":"https://api.github.com/users/P33M","html_url":"https://github.com/P33M","followers_url":"https://api.github.com/users/P33M/followers","following_url":"https://api.github.com/users/P33M/following{/other_user}","gists_url":"https://api.github.com/users/P33M/gists{/gist_id}","starred_url":"https://api.github.com/users/P33M/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/P33M/subscriptions","organizations_url":"https://api.github.com/users/P33M/orgs","repos_url":"https://api.github.com/users/P33M/repos","events_url":"https://api.github.com/users/P33M/events{/privacy}","received_events_url":"https://api.github.com/users/P33M/received_events","type":"User","site_admin":false},"created_at":"2015-08-17T15:46:47Z","updated_at":"2015-08-17T15:46:47Z","body":"On BCM2835 you have a single core which has to handle all interrupts. The USB fiq was implemented because of various hardware requirements meaning any interrupt latency over 125uS caused problems. In this case, the maximum acceptable latency then turns into ~500uS for this application - approximately half the USB device update rate. Very few commonly-encountered kernel operations disable interrupts for this length of time.\r\n\r\nIf the SPI driver is spending a lot of time with interrupts disabled or in a HardIRQ context, then this is a bad behaviour. Using DMA is a solution for this (one interrupt on completion of DMA).\r\n\r\nOn BCM2836, there is no vectored interrupt controller. There is simply a mux that selects which core GPU IRQ or GPU FIQ interrupts go to - which is then chained into the core-local interrupt handling. One possibility that I have yet to implement (had working, but then a kernel version update broke it) is to (ab)use a CPU local mailbox such that USB interrupts occur on a single designated core, but this will not be possible to implement for any other interrupt source."}}