--- /dev/null
+From 306320034e8fbe7ee1cc4f5269c55658b4612048 Mon Sep 17 00:00:00 2001
+From: Bernhard Seibold <mail@bernhard-seibold.de>
+Date: Fri, 2 Jun 2023 15:30:29 +0200
+Subject: serial: lantiq: add missing interrupt ack
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Bernhard Seibold <mail@bernhard-seibold.de>
+
+commit 306320034e8fbe7ee1cc4f5269c55658b4612048 upstream.
+
+Currently, the error interrupt is never acknowledged, so once active it
+will stay active indefinitely, causing the handler to be called in an
+infinite loop.
+
+Fixes: 2f0fc4159a6a ("SERIAL: Lantiq: Add driver for MIPS Lantiq SOCs.")
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Bernhard Seibold <mail@bernhard-seibold.de>
+Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
+Message-ID: <20230602133029.546-1-mail@bernhard-seibold.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/tty/serial/lantiq.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/drivers/tty/serial/lantiq.c
++++ b/drivers/tty/serial/lantiq.c
+@@ -263,6 +263,7 @@ lqasc_err_int(int irq, void *_port)
+ unsigned long flags;
+ struct uart_port *port = (struct uart_port *)_port;
+ spin_lock_irqsave(<q_asc_lock, flags);
++ ltq_w32(ASC_IRNCR_EIR, port->membase + LTQ_ASC_IRNCR);
+ /* clear any pending interrupts */
+ ltq_w32_mask(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
+ ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);