serial: lantiq: add missing interrupt ack

BugLink: https://bugs.launchpad.net/bugs/2033931
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index a58e9277dfad8752b10af8ca5bd8ad7383984531..f1387f1024dbb336b2304966d990b563ba42f0db 100644 (file)
--- 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);