diff options
| -rw-r--r-- | drivers/usb/serial/usb-serial.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 3c8923f62ed1..99188c92068b 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -32,6 +32,7 @@ #include <linux/mutex.h> #include <linux/list.h> #include <linux/uaccess.h> +#include <linux/serial.h> #include <linux/usb.h> #include <linux/usb/serial.h> #include "pl2303.h" @@ -184,6 +185,7 @@ static int serial_open (struct tty_struct *tty, struct file *filp) struct usb_serial_port *port; unsigned int portNumber; int retval = 0; + int first = 0; dbg("%s", __func__); @@ -223,7 +225,7 @@ static int serial_open (struct tty_struct *tty, struct file *filp) /* If the console is attached, the device is already open */ if (port->port.count == 1 && !port->console) { - + first = 1; /* lock this module before we call it * this may fail, which means we must bail out, * safe because we are called with BKL held */ @@ -246,13 +248,21 @@ static int serial_open (struct tty_struct *tty, struct file *filp) if (retval) goto bailout_interface_put; mutex_unlock(&serial->disc_mutex); + set_bit(ASYNCB_INITIALIZED, &port->port.flags); } mutex_unlock(&port->mutex); /* Now do the correct tty layer semantics */ retval = tty_port_block_til_ready(&port->port, tty, filp); - if (retval == 0) + if (retval == 0) { + if (!first) + usb_serial_put(serial); return 0; - + } + mutex_lock(&port->mutex); + if (first == 0) + goto bailout_mutex_unlock; + /* Undo the initial port actions */ + mutex_lock(&serial->disc_mutex); bailout_interface_put: usb_autopm_put_interface(serial->interface); bailout_module_put: @@ -411,7 +421,6 @@ static int serial_chars_in_buffer(struct tty_struct *tty) struct usb_serial_port *port = tty->driver_data; dbg("%s = port %d", __func__, port->number); - WARN_ON(!port->port.count); /* if the device was unplugged then any remaining characters fell out of the connector ;) */ if (port->serial->disconnected) |