USB: serial: fix infinite wait_until_sent timeout

commit f528bf4f57e43d1af4b2a5c97f09e43e0338c105 upstream.

Make sure to handle an infinite timeout (0).

Note that wait_until_sent is currently never called with a 0-timeout
argument due to a bug in tty_wait_until_sent.

Fixes: dcf010503966 ("USB: serial: add generic wait_until_sent
implementation")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 8335b48..a10648d 100644 (file)
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -261,7 +261,8 @@ void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)
         * character or at least one jiffy.
         */
        period = max_t(unsigned long, (10 * HZ / bps), 1);
-       period = min_t(unsigned long, period, timeout);
+       if (timeout)
+               period = min_t(unsigned long, period, timeout);
 
        dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
                                        __func__, jiffies_to_msecs(timeout),
@@ -271,7 +272,7 @@ void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)
                schedule_timeout_interruptible(period);
                if (signal_pending(current))
                        break;
-               if (time_after(jiffies, expire))
+               if (timeout && time_after(jiffies, expire))
                        break;
        }
 }