Merge tag 'tty-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty fixes from Greg KH:
 "Here are some small tty/serial fixes for 5.10-rc5 that resolve some
  reported issues:

   - speakup crash when telling the kernel to use a device that isn't
     really there

   - imx serial driver fixes for reported problems

   - ar933x_uart driver fix for probe error handling path

  All have been in linux-next for a while with no reported issues"

* tag 'tty-5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: ar933x_uart: disable clk on error handling path in probe
  tty: serial: imx: keep console clocks always on
  speakup: Do not let the line discipline be used several times
  tty: serial: imx: fix potential deadlock

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/accessibility/speakup/spk_ttyio.c b/drivers/accessibility/speakup/spk_ttyio.c
index ecc39983e946..669392f31d4e 100644
--- a/drivers/accessibility/speakup/spk_ttyio.c
+++ b/drivers/accessibility/speakup/spk_ttyio.c
@@ -49,15 +49,25 @@ static int spk_ttyio_ldisc_open(struct tty_struct *tty)
 
 	if (!tty->ops->write)
 		return -EOPNOTSUPP;
+
+	mutex_lock(&speakup_tty_mutex);
+	if (speakup_tty) {
+		mutex_unlock(&speakup_tty_mutex);
+		return -EBUSY;
+	}
 	speakup_tty = tty;
 
 	ldisc_data = kmalloc(sizeof(*ldisc_data), GFP_KERNEL);
-	if (!ldisc_data)
+	if (!ldisc_data) {
+		speakup_tty = NULL;
+		mutex_unlock(&speakup_tty_mutex);
 		return -ENOMEM;
+	}
 
 	init_completion(&ldisc_data->completion);
 	ldisc_data->buf_free = true;
 	speakup_tty->disc_data = ldisc_data;
+	mutex_unlock(&speakup_tty_mutex);
 
 	return 0;
 }