关于UsbDeviceConnection的claimInterface

对于usb手柄而言，调用后会将/dev/input/eventX设备remove掉（getevent将不会接收到任何该usb设备的输入事件）

frameworks/base/core/jni/android_hardware_UsbDeviceConnection.cpp

static jboolean
android_hardware_UsbDeviceConnection_claim_interface(JNIEnv *env, jobject thiz,
        int interfaceID, jboolean force)
{
    struct usb_device* device = get_device_from_object(env, thiz);
    if (!device) {
        ALOGE("device is closed in native_claim_interface");
        return -1;
    }

    int ret = usb_device_claim_interface(device, interfaceID);
    if (ret && force && errno == EBUSY) {
        // disconnect kernel driver and try again
        usb_device_connect_kernel_driver(device, interfaceID, false);
        ret = usb_device_claim_interface(device, interfaceID);
    }
    return ret == 0;
}

system/core/libusbhost/usbhost.c

int usb_device_claim_interface(struct usb_device *device, unsigned int interface)
{
    return ioctl(device->fd, USBDEVFS_CLAIMINTERFACE, &interface);
}

int usb_device_connect_kernel_driver(struct usb_device *device,
        unsigned int interface, int connect)
{
    struct usbdevfs_ioctl ctl;

    ctl.ifno = interface;
    ctl.ioctl_code = (connect ? USBDEVFS_CONNECT : USBDEVFS_DISCONNECT);
    ctl.data = NULL;
    return ioctl(device->fd, USBDEVFS_IOCTL, &ctl);
}