Resetting the USB Bus under linux
Posted by Benjamin Close on September 15, 2008 under UniSA | 
3 Comments to Read
Today Snappy, the little photo box we have taking photos of the new Bruce Lab, broke again. Hence I quickly came up with a way of resetting the USB device under linux based on libusb. Sadly whilst I can confirm this does reset the device gphoto2 still doesn’t like our little Canon Ixus 400 and we still get timeouts after about 12 hours of taking photos – 1 photo every 2 minutes. Below is the hack of a program I used.
To compile use: gcc -o outputname resetusb.c -lusb
#include <stdio.h>
#include <usb.h>
int main(void)
{
struct usb_bus *busses;
usb_init();
usb_find_busses();
usb_find_devices();
busses = usb_get_busses();
struct usb_bus *bus;
int c, i, a;
/* ... */
for (bus = busses; bus; bus = bus->next) {
struct usb_device *dev;
int val;
usb_dev_handle *junk;
for (dev = bus->devices; dev; dev = dev->next) {
char buf[1024];
junk = usb_open ( dev );
usb_get_string_simple(junk,2,buf,1023);
if ( junk == NULL ){
printf("Can't open %p (%s)\n", dev, buf );
} else {
val = usb_reset(junk);
printf( "reset %p %d (%s)\n", dev, val, buf );
}
usb_close(junk);
}
}
}