#include <linux/init.h>
#include <linux/slab.h>
#include <linux/errno.h>
+#include <linux/mutex.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
};
MODULE_DEVICE_TABLE (usb, id_table);
+static DEFINE_MUTEX(open_disc_mutex);
+
struct usb_lcd {
struct usb_device * udev; /* init: probe_lcd */
return -ENODEV;
}
+ mutex_lock(&open_disc_mutex);
dev = usb_get_intfdata(interface);
- if (!dev)
+ if (!dev) {
+ mutex_unlock(&open_disc_mutex);
return -ENODEV;
+ }
/* increment our usage count for the device */
kref_get(&dev->kref);
+ mutex_unlock(&open_disc_mutex);
/* grab a power reference */
r = usb_autopm_get_interface(interface);
static void lcd_write_bulk_callback(struct urb *urb)
{
struct usb_lcd *dev;
+ int status = urb->status;
dev = (struct usb_lcd *)urb->context;
/* sync/async unlink faults aren't errors */
- if (urb->status &&
- !(urb->status == -ENOENT ||
- urb->status == -ECONNRESET ||
- urb->status == -ESHUTDOWN)) {
+ if (status &&
+ !(status == -ENOENT ||
+ status == -ECONNRESET ||
+ status == -ESHUTDOWN)) {
dbg("USBLCD: %s - nonzero write bulk status received: %d",
- __FUNCTION__, urb->status);
+ __FUNCTION__, status);
}
/* free up our allocated buffer */
struct usb_lcd *dev;
int minor = interface->minor;
+ mutex_lock(&open_disc_mutex);
dev = usb_get_intfdata(interface);
usb_set_intfdata(interface, NULL);
+ mutex_unlock(&open_disc_mutex);
/* give back our minor */
usb_deregister_dev(interface, &lcd_class);