serial: lantiq: add missing interrupt ack

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>

diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 22df94f107e5415f03a5b0c44983e39b3eb7b03d..3be36bcd69e01a98ca61d24b57bfcfcf65e8a2dc 100644 (file)
--- 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(&ltq_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);