UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

USB: serial: grab disconnect mutex in chars_in_buffer 

Grab disconnect mutex in chars_in_buffer before checking disconnected
flag or calling driver specific function.

This allows subdrivers to query any hardware buffer status without
having to handle the locking themselves.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2013-01-14 16:52:56 +01:00 committed by Greg Kroah-Hartman
parent fcdb6a2190
commit 810360a035
1 changed files with 10 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/usb/serial/usb-serial.c
View File

@ -361,15 +361,21 @@ static int serial_write_room(struct tty_struct *tty)
static int serial_chars_in_buffer(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct usb_serial *serial = port->serial;
int count = 0;
dev_dbg(tty->dev, "%s - port %d\n", __func__, port->number);
mutex_lock(&serial->disc_mutex);
/* if the device was unplugged then any remaining characters
fell out of the connector ;) */
if (port->serial->disconnected)
return 0;
/* pass on to the driver specific version of this function */
return port->serial->type->chars_in_buffer(tty);
if (serial->disconnected)
count = 0;
else
count = serial->type->chars_in_buffer(tty);
mutex_unlock(&serial->disc_mutex);
return count;
}
static void serial_throttle(struct tty_struct *tty)