Merge 4.15-rc3 into tty-next

We want the serial/tty fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 23 insertions, 3 deletions

diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index 75f312ed96e8..c2629ab1bbcf 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -27,23 +27,41 @@ static int ttyport_receive_buf(struct tty_port *port, const unsigned char *cp,
 {
         struct serdev_controller *ctrl = port->client_data;
         struct serport *serport = serdev_controller_get_drvdata(ctrl);
+        int ret;
 
         if (!test_bit(SERPORT_ACTIVE, &serport->flags))
                 return 0;
 
-        return serdev_controller_receive_buf(ctrl, cp, count);
+        ret = serdev_controller_receive_buf(ctrl, cp, count);
+
+        dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
+                                "receive_buf returns %d (count = %zu)\n",
+                                ret, count);
+        if (ret < 0)
+                return 0;
+        else if (ret > count)
+                return count;
+
+        return ret;
 }
 
 static void ttyport_write_wakeup(struct tty_port *port)
 {
         struct serdev_controller *ctrl = port->client_data;
         struct serport *serport = serdev_controller_get_drvdata(ctrl);
+        struct tty_struct *tty;
+
+        tty = tty_port_tty_get(port);
+        if (!tty)
+                return;
 
-        if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &port->tty->flags) &&
+        if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
             test_bit(SERPORT_ACTIVE, &serport->flags))
                 serdev_controller_write_wakeup(ctrl);
 
-        wake_up_interruptible_poll(&port->tty->write_wait, POLLOUT);
+        wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+
+        tty_kref_put(tty);
 }
 
 static const struct tty_port_client_operations client_ops = {
@@ -139,8 +157,10 @@ static void ttyport_close(struct serdev_controller *ctrl)
 
         clear_bit(SERPORT_ACTIVE, &serport->flags);
 
+        tty_lock(tty);
         if (tty->ops->close)
                 tty->ops->close(tty, NULL);
+        tty_unlock(tty);
 
         tty_release_struct(tty, serport->tty_idx);
 }