staging: greybus: uart: fix TIOCSSERIAL jiffies conversions

The port close_delay and closing_wait parameters set by TIOCSSERIAL are
specified in jiffies and not milliseconds.

Add the missing conversions so that TIOCSSERIAL works as expected also
when HZ is not 1000.

Fixes: e68453ed28 ("greybus: uart-gb: now builds, more framework added")
Cc: stable@vger.kernel.org	# 4.9
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-6-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/greybus/uart.c

@@ -614,10 +614,12 @@ static int get_serial_info(struct tty_struct *tty,
 	ss->line = gb_tty->minor;
 	ss->xmit_fifo_size = 16;
 	ss->baud_base = 9600;
-	ss->close_delay = gb_tty->port.close_delay / 10;
+	ss->close_delay = jiffies_to_msecs(gb_tty->port.close_delay) / 10;
 	ss->closing_wait =
 		gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
-		ASYNC_CLOSING_WAIT_NONE : gb_tty->port.closing_wait / 10;
+		ASYNC_CLOSING_WAIT_NONE :
+		jiffies_to_msecs(gb_tty->port.closing_wait) / 10;
+
 	return 0;
 }
 
@@ -629,9 +631,10 @@ static int set_serial_info(struct tty_struct *tty,
 	unsigned int close_delay;
 	int retval = 0;
 
-	close_delay = ss->close_delay * 10;
+	close_delay = msecs_to_jiffies(ss->close_delay * 10);
 	closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
-			ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10;
+			ASYNC_CLOSING_WAIT_NONE :
+			msecs_to_jiffies(ss->closing_wait * 10);
 
 	mutex_lock(&gb_tty->port.mutex);
 	if (!capable(CAP_SYS_ADMIN)) {