This is a note to let you know that I've just added the patch titled serial: lantiq: add missing interrupt ack to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-lantiq-add-missing-interrupt-ack.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 306320034e8fbe7ee1cc4f5269c55658b4612048 Mon Sep 17 00:00:00 2001 From: Bernhard Seibold <mail@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx> Signed-off-by: Bernhard Seibold <mail@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Message-ID: <20230602133029.546-1-mail@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/lantiq.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/tty/serial/lantiq.c +++ b/drivers/tty/serial/lantiq.c @@ -274,6 +274,7 @@ lqasc_err_int(int irq, void *_port) struct ltq_uart_port *ltq_port = to_ltq_uart_port(port); spin_lock_irqsave(<q_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); Patches currently in stable-queue which might be from mail@xxxxxxxxxxxxxxxxxxx are queue-5.4/serial-lantiq-add-missing-interrupt-ack.patch