Hi, * Romain Naour <romain.naour@xxxxxxxx> [220209 09:13]: > Le 07/02/2022 à 09:04, Tony Lindgren a écrit : > > Interesting, what's the exception you get with the -rt kernel? Is it an > > unhandled external abort or something else? > > "asynchronous external abort" OK > Maybe there is something wrong with the smart-standby or smart-idle feature in > the UART IP ? I'm not sure. Could be that too, but maybe it's as simple as the patch below. Care to give it a try? > Are you able to reproduce it ? > Maybe on a IDK574 or a Beaglebone-AI board ? Not sure why I'm not seeing this one with my test systems.. Have not tried with the RT patches for a while though. Regards, Tony 8< ------- diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -163,6 +163,8 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) struct omap8250_priv *priv = up->port.private_data; u8 lcr; + pm_runtime_get_sync(port->dev); + serial8250_do_set_mctrl(port, mctrl); if (!mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS)) { @@ -179,6 +181,9 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) serial_out(up, UART_EFR, priv->efr); serial_out(up, UART_LCR, lcr); } + + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); } /*