[PATCH] serial: lantiq: add missing interrupt ack

[Bernhard Seibold <mail@xxxxxxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxx>
Signed-off-by: Bernhard Seibold <mail@xxxxxxxxxxxxxxxxxxx>
---
 drivers/tty/serial/lantiq.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index a58e9277dfad..f1387f1024db 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -250,6 +250,7 @@ lqasc_err_int(int irq, void *_port)
 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
 
 	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(ASC_IRNCR_EIR, port->membase + LTQ_ASC_IRNCR);
 	/* clear any pending interrupts */
 	asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
 		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
-- 
2.34.1