Both the dp_write_urb_in_use flag and dp_out_buf_len counter should be
accessed while holding the driver port lock. Add the missing locking to
chars_in_buffer and clean up the implementation somewhat by using a
common exit path.
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/serial/digi_acceleport.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index a4194b70a6fe..754c66ff0fc1 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -1044,17 +1044,19 @@ static unsigned int digi_chars_in_buffer(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct digi_port *priv = usb_get_serial_port_data(port);
+ unsigned long flags;
+ unsigned int chars;
- if (priv->dp_write_urb_in_use) {
- dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
- priv->dp_port_num, port->bulk_out_size - 2);
- return port->bulk_out_size - 2;
- } else {
- dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
- priv->dp_port_num, priv->dp_out_buf_len);
- return priv->dp_out_buf_len;
- }
+ spin_lock_irqsave(&priv->dp_port_lock, flags);
+ if (priv->dp_write_urb_in_use)
+ chars = port->bulk_out_size - 2;
+ else
+ chars = priv->dp_out_buf_len;
+ spin_unlock_irqrestore(&priv->dp_port_lock, flags);
+ dev_dbg(&port->dev, "%s: port=%d, chars=%d\n", __func__,
+ priv->dp_port_num, chars);
+ return chars;
}
static void digi_dtr_rts(struct usb_serial_port *port, int on)
--
2.26.3
