# lsusb
Bus 002 Device 002: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 009: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 002 Device 004: ID 046d:c31c Logitech, Inc. Keyboard K120 for Business
Bus 002 Device 005: ID 413c:3012 Dell Computer Corp. Optical Wheel Mouse
Bus 002 Device 017: ID 0572:1329 Conexant Systems (Rockwell), Inc.

# lsusb
Bus 002 Device 002: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 009: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 002 Device 004: ID 046d:c31c Logitech, Inc. Keyboard K120 for Business
Bus 002 Device 005: ID 413c:3012 Dell Computer Corp. Optical Wheel Mouse

# tail -f /var/log/messages
CuBox ModemManager[406]: <info>  (tty/ttyACM0): released by modem /sys/devices/soc0/soc.1/2100000.aips-bus/2184200.usb/ci_hdrc.1/usb2/2-1/2-1.4
2014-12-19T18:05:30.397588-05:00 CuBox kernel: [26167.864681] usb 2-1.4: reset full-speed USB device number 23 using ci_hdrc
2014-12-19T18:05:30.473544-05:00 CuBox kernel: [26167.941086] cdc_acm 2-1.4:1.0: ttyACM0: USB ACM device
2014-12-19T18:05:34.446275-05:00 CuBox ModemManager[406]: <info>  Creating modem with plugin 'Generic' and '1' ports
2014-12-19T18:05:34.456924-05:00 CuBox ModemManager[406]: <info>  Modem for device at '/sys/devices/soc0/soc.1/2100000.aips-bus/2184200.usb/ci_hdrc.1/usb2/2-1/2-1.4' successfully created
2014-12-19T18:05:34.569078-05:00 CuBox ModemManager[406]: <warn>  Modem couldn't be initialized: couldn't load current capabilities: Failed to determine modem capabilities.

/* usbreset -- send a USB port reset to a USB device */
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <linux/usbdevice_fs.h>

int main(int argc, char **argv)
{
    const char *filename;
    int fd;
    int rc;

    if (argc != 2)
    {
        fprintf(stderr, "Usage: usbreset device-filename\n");
        return 1;
    }
    filename = argv[1];
    fd = open(filename, O_WRONLY);

    if (fd < 0)
    {
        perror("Error opening output file");
        return 1;
    }
    printf("Resetting USB device %s\n", filename);
    rc = ioctl(fd, USBDEVFS_RESET, 0);

    if (rc < 0)
    {
        perror("Error in ioctl");
        return 1;
    }
    printf("Reset successful\n");

    close(fd);
    return 0;
}