@@ -338,6 +338,11 @@ printer_open(struct inode *inode, struct file *fd)
spin_lock_irqsave(&dev->lock, flags);
+ if (dev->interface < 0) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return -ENODEV;
+ }
+
if (!dev->printer_cdev_open) {
dev->printer_cdev_open = 1;
fd->private_data = dev;
@@ -430,6 +435,12 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
mutex_lock(&dev->lock_printer_io);
spin_lock_irqsave(&dev->lock, flags);
+ if (dev->interface < 0) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock_printer_io);
+ return -ENODEV;
+ }
+
/* We will use this flag later to check if a printer reset happened
* after we turn interrupts back on.
*/
@@ -561,6 +572,12 @@ printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
mutex_lock(&dev->lock_printer_io);
spin_lock_irqsave(&dev->lock, flags);
+ if (dev->interface < 0) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock_printer_io);
+ return -ENODEV;
+ }
+
/* Check if a printer reset happens while we have interrupts on */
dev->reset_printer = 0;
@@ -667,6 +684,13 @@ printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
inode_lock(inode);
spin_lock_irqsave(&dev->lock, flags);
+
+ if (dev->interface < 0) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ inode_unlock(inode);
+ return -ENODEV;
+ }
+
tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
spin_unlock_irqrestore(&dev->lock, flags);
@@ -689,6 +713,13 @@ printer_poll(struct file *fd, poll_table *wait)
mutex_lock(&dev->lock_printer_io);
spin_lock_irqsave(&dev->lock, flags);
+
+ if (dev->interface < 0) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ mutex_unlock(&dev->lock_printer_io);
+ return EPOLLERR | EPOLLHUP;
+ }
+
setup_rx_reqs(dev);
spin_unlock_irqrestore(&dev->lock, flags);
mutex_unlock(&dev->lock_printer_io);
@@ -722,6 +753,11 @@ printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
spin_lock_irqsave(&dev->lock, flags);
+ if (dev->interface < 0) {
+ spin_unlock_irqrestore(&dev->lock, flags);
+ return -ENODEV;
+ }
+
switch (code) {
case GADGET_GET_PRINTER_STATUS:
status = (int)dev->printer_status;