On 2024-03-22 01:15, Tony Lindgren wrote: > * Nick Bowler <nbowler@xxxxxxxxxx> [240322 04:29]: >> I bisected to this commit: >> >> commit 45a3a8ef81291b63a2b50a1a145857dd9fc05e89 >> Author: Tony Lindgren <tony@xxxxxxxxxxx> >> Date: Mon Nov 13 10:07:53 2023 +0200 >> >> serial: core: Revert checks for tx runtime PM state >> >> Reverting this commit on top of Linux 6.8 is sufficient to get the >> system booting again. > > Thanks a lot for bisecting and reporting the issue. > > Can you please test if the following change to add back the check for > !pm_runtime_active() is enough to fix the issue? I applied the below patch on top of 6.8 and unfortunately it does _not_ fix the problem (no obvious change in behaviour). Thanks, Nick > 8< ----------------------- > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > --- 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->dev) || pm_runtime_active(&port_dev->dev)) > port->ops->start_tx(port); > pm_runtime_mark_last_busy(&port_dev->dev); > pm_runtime_put_autosuspend(&port_dev->dev);