USB: serial: digi_acceleport: add chars_in_buffer locking

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.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2021-05-19 11:20:02 +02:00
parent 3aed3af202
commit dcbc0ae4f8
1 changed files with 11 additions and 9 deletions

View File

@ -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)