MODULE_PARM_DESC(debug, "debug=1 enables debugging messages");
static struct usb_driver iowarrior_driver;
+static DEFINE_MUTEX(iowarrior_open_disc_lock);
/*--------------*/
/* data */
mutex_lock(&dev->mutex);
/* verify that the device wasn't unplugged */
- if (dev == NULL || !dev->present) {
+ if (!dev->present) {
retval = -ENODEV;
goto exit;
}
return -ENODEV;
}
+ mutex_lock(&iowarrior_open_disc_lock);
dev = usb_get_intfdata(interface);
- if (!dev)
+ if (!dev) {
+ mutex_unlock(&iowarrior_open_disc_lock);
return -ENODEV;
+ }
mutex_lock(&dev->mutex);
+ mutex_unlock(&iowarrior_open_disc_lock);
/* Only one process can open each device, no sharing. */
if (dev->opened) {
* would use "struct net_driver" instead, and a serial
* device would use "struct tty_driver".
*/
-static struct file_operations iowarrior_fops = {
+static const struct file_operations iowarrior_fops = {
.owner = THIS_MODULE,
.write = iowarrior_write,
.read = iowarrior_read,
int minor;
dev = usb_get_intfdata(interface);
+ mutex_lock(&iowarrior_open_disc_lock);
usb_set_intfdata(interface, NULL);
minor = dev->minor;
dev->present = 0;
mutex_unlock(&dev->mutex);
+ mutex_unlock(&iowarrior_open_disc_lock);
if (dev->opened) {
/* There is a process that holds a filedescriptor to the device ,