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 c892f3c7d1abc1b6f2ee7e2755e09f01db20de60..112a2f5f6ac3fe65084d0067a52f3ef80076f00a 100644 (file)
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -278,6 +278,7 @@ 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);