On 2024-02-04, Yicong Yang <yangyicong@xxxxxxxxxx> wrote: > diff --git a/drivers/tty/serial/serial_port.c b/drivers/tty/serial/serial_port.c > index 88975a4df306..60d1eec6b6b7 100644 > --- a/drivers/tty/serial/serial_port.c > +++ b/drivers/tty/serial/serial_port.c > @@ -46,8 +46,28 @@ static int serial_port_runtime_resume(struct device *dev) > return 0; > } > > +static int serial_port_runtime_suspend(struct device *dev) > +{ > + struct serial_port_device *port_dev = to_serial_base_port_device(dev); > + struct uart_port *port; > + unsigned long flags; > + > + port = port_dev->port; > + > + if (port->flags & UPF_DEAD) > + return 0; > + > + spin_lock_irqsave(&port->lock, flags); > + if (__serial_port_busy(port)) > + pm_request_resume(dev); > + spin_unlock_irqrestore(&port->lock, flags); Please use the wrapper functions for the uart port lock: uart_port_lock_irqsave() uart_port_unlock_irqrestore() John Ogness