* Johan Hovold <johan@xxxxxxxxxx> [231004 09:14]: > On Wed, Oct 04, 2023 at 12:03:20PM +0300, Tony Lindgren wrote: > > The serial port device and serdev device are siblings of the physical > > serial port controller device as seen in the hierarcy printed out by > > Maximilian. > > Yeah, and that's precisely the broken part. Keeping the serdev > controller active is supposed to keep the serial controller active. Your > serial core rework appears to have broken just that. Hmm OK good point, tx can currently have an extra delay if a serdev device is active, and the serial port controller device is not active. So we can check for active port->dev instead of &port_dev->dev though to know when when start_tx() is safe to do as below. Thanks. Tony 8< ----------------- diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 6207f0051f23d..defecc5b04422 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -156,7 +156,7 @@ static void __uart_start(struct uart_state *state) * enabled, serial_port_runtime_resume() calls start_tx() again * after enabling the device. */ - if (pm_runtime_active(&port_dev->dev)) + if (!pm_runtime_enabled(port->dev) || pm_runtime_active(port->dev)) port->ops->start_tx(port); pm_runtime_mark_last_busy(&port_dev->dev); pm_runtime_put_autosuspend(&port_dev->dev);
