diff options
Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
| -rw-r--r-- | drivers/usb/serial/usb-serial.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 5bc023c7389..8bc8337c99c 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -30,6 +30,7 @@ #include <linux/list.h> #include <linux/smp_lock.h> #include <asm/uaccess.h> +#include <asm/semaphore.h> #include <linux/usb.h> #include "usb-serial.h" #include "pl2303.h" @@ -190,6 +191,9 @@ static int serial_open (struct tty_struct *tty, struct file * filp) port = serial->port[portNumber]; if (!port) return -ENODEV; + + if (down_interruptible(&port->sem)) + return -ERESTARTSYS; ++port->open_count; @@ -215,6 +219,7 @@ static int serial_open (struct tty_struct *tty, struct file * filp) goto bailout_module_put; } + up(&port->sem); return 0; bailout_module_put: @@ -222,6 +227,7 @@ bailout_module_put: bailout_kref_put: kref_put(&serial->kref, destroy_serial); port->open_count = 0; + up(&port->sem); return retval; } @@ -234,8 +240,10 @@ static void serial_close(struct tty_struct *tty, struct file * filp) dbg("%s - port %d", __FUNCTION__, port->number); + down(&port->sem); + if (port->open_count == 0) - return; + goto out; --port->open_count; if (port->open_count == 0) { @@ -253,6 +261,9 @@ static void serial_close(struct tty_struct *tty, struct file * filp) } kref_put(&port->serial->kref, destroy_serial); + +out: + up(&port->sem); } static int serial_write (struct tty_struct * tty, const unsigned char *buf, int count) @@ -774,6 +785,7 @@ int usb_serial_probe(struct usb_interface *interface, port->number = i + serial->minor; port->serial = serial; spin_lock_init(&port->lock); + sema_init(&port->sem, 1); INIT_WORK(&port->work, usb_serial_port_softint, port); serial->port[i] = port; } |