X-Fi USB HD - switching from USB1.1 to USB2?

[Pavel Hofman]

Hi,

The X-Fi USB HD device (and likely the similar 5.1 model too) can run at
USB1.1 (with limited samplerates) and USB2 modes (with full specs). In
linux the device stays at USB1.1. If connected to Windows with stock
windows USB driver the same happens. However, when the Creative
proprietary driver is installed, the device switches to USB2 and
supports all features. When rebooting to linux without re-plugging, the
USB2 mode stays and the device offers its USB2 configurations to
snd-usb-audio.

We captured USB packets in linux and Win7 with wireshark - both dumps
are included. The windows dump shows that in windows as well as in linux
the device starts as device 3.5.0 at USB1.1:

DEVICE DESCRIPTOR
    bLength: 18
    bDescriptorType: 0x01 (DEVICE)
    bcdUSB: 0x0110
    bDeviceClass: Device (0x00)
    bDeviceSubClass: 0
    bDeviceProtocol: 0 (Use class code info from Interface Descriptors)
    bMaxPacketSize0: 64
    idVendor: Creative Technology, Ltd (0x041e)
    idProduct: Unknown (0x30d7)
    bcdDevice: 0x0100
    iManufacturer: 1
    iProduct: 2
    iSerialNumber: 3
    bNumConfigurations: 1


After USB1.1 enumeration, the windows host controlled by the vendor
driver sends a request USR_FUNCTION_ABORT_PIPE to EP IN 6:


The EP IN 6  descriptor (from USB1.1 configuration):

ENDPOINT DESCRIPTOR
    bLength: 7
    bDescriptorType: 0x05 (ENDPOINT)
    bEndpointAddress: 0x86  IN  Endpoint:6
        1... .... = Direction: IN Endpoint
        .... 0110 = Endpoint Number: 0x6
    bmAttributes: 0x03
        .... ..11 = Transfertype: Interrupt-Transfer (0x3)
    wMaxPacketSize: 64
        ...0 0... .... .... = Transactions per microframe: 1 (0)
        .... ..00 0100 0000 = Maximum Packet Size: 64
    bInterval: 1

The request sent by the host is:
USB URB
    [Source: host]
    [Destination: 3.5.6]
    USBPcap pseudoheader length: 27
    IRP ID: 0xfffffa80073ee120
    IRP USBD_STATUS: USBD_STATUS_SUCCESS (0x00000000)
    URB Function: URB_FUNCTION_ABORT_PIPE (0x0002)
    IRP information: 0x00, Direction: FDO -> PDO
    URB bus id: 3
    Device address: 5
    Endpoint: 0x86, Direction: IN
    URB transfer type: USB IRP Info (0xfe)
    Packet Data Length: 0


The device responds with a proprietary response, with a different source
3.5.127:
USB URB
    [Source: 3.5.127]
    [Destination: host]
    USBPcap pseudoheader length: 27
    IRP ID: 0xfffffa80073ee120
    IRP USBD_STATUS: USBD_STATUS_SUCCESS (0x00000000)
    URB Function: URB_FUNCTION_ABORT_PIPE (0x0002)
    IRP information: 0x01, Direction: PDO -> FDO
        0000 000. = Reserved: 0x00
        .... ...1 = Direction: PDO -> FDO (0x1)
    URB bus id: 3
    Device address: 5
    Endpoint: 0xff, Direction: IN
        1... .... = Direction: IN (1)
        .... 1111 = Endpoint number: 15
    URB transfer type: Unknown (0xff)
        [Expert Info (Error/Malformed): USBPcap did not recognize URB
Function code (report to desowin.org/USBPcap)]
            [USBPcap did not recognize URB Function code (report to
desowin.org/USBPcap)]
            [Severity level: Error]
            [Group: Malformed]
    Packet Data Length: 0


Immediately after that the device re-connects as 3.6.0 and reports its
USB2.0 description:

DEVICE DESCRIPTOR
    bLength: 18
    bDescriptorType: 0x01 (DEVICE)
    bcdUSB: 0x0200
    bDeviceClass: Device (0x00)
    bDeviceSubClass: 0
    bDeviceProtocol: 0 (Use class code info from Interface Descriptors)
    bMaxPacketSize0: 64
    idVendor: Creative Technology, Ltd (0x041e)
    idProduct: Unknown (0x30d7)
    bcdDevice: 0x0100
    iManufacturer: 1
    iProduct: 2
    iSerialNumber: 3
    bNumConfigurations: 1

This is a regular USB-audio device which works OK in snd-usb-audio, as
tested after rebooting from windows to linux.

Please is there any similar case handled by the existing alsa usb driver
which we could try to modify and test? My USB skills are not up to
writing the required code myself from scratch, unfortunately.

Thanks a lot,

Pavel.



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