diff options
Diffstat (limited to 'drivers/usb/serial/keyspan_pda.c')
| -rw-r--r-- | drivers/usb/serial/keyspan_pda.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c index 6ce292ef1c47..b650fb4754b4 100644 --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -636,14 +636,19 @@ static int keyspan_pda_write_room (struct usb_serial_port *port) static int keyspan_pda_chars_in_buffer (struct usb_serial_port *port) { struct keyspan_pda_private *priv; + unsigned long flags; + int ret = 0; priv = usb_get_serial_port_data(port); /* when throttled, return at least WAKEUP_CHARS to tell select() (via n_tty.c:normal_poll() ) that we're not writeable. */ + + spin_lock_irqsave(&port->lock, flags); if (port->write_urb_busy || priv->tx_throttled) - return 256; - return 0; + ret = 256; + spin_unlock_irqrestore(&port->lock, flags); + return ret; } |