6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pin-yen Lin <treapking@xxxxxxxxxxxx> commit 4244f830a56058ee0670d80e7ac9fd7c982eb480 upstream. When Rx in-band wakeup is enabled, set RTS to true in mtk8250_shutdown() so the connected device can still send message and trigger IRQ when the system is suspended. Fixes: 18c9d4a3c249 ("serial: When UART is suspended, set RTS to false") Cc: stable <stable@xxxxxxxxxx> Signed-off-by: Pin-yen Lin <treapking@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240424130619.2924456-1-treapking@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_mtk.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -209,15 +209,19 @@ static int mtk8250_startup(struct uart_p static void mtk8250_shutdown(struct uart_port *port) { -#ifdef CONFIG_SERIAL_8250_DMA struct uart_8250_port *up = up_to_u8250p(port); struct mtk8250_data *data = port->private_data; + int irq = data->rx_wakeup_irq; +#ifdef CONFIG_SERIAL_8250_DMA if (up->dma) data->rx_status = DMA_RX_SHUTDOWN; #endif - return serial8250_do_shutdown(port); + serial8250_do_shutdown(port); + + if (irq >= 0) + serial8250_do_set_mctrl(&up->port, TIOCM_RTS); } static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)