Re: PROBLEM: Sun Ultra 60 hangs on boot since Linux 6.8

[Nick Bowler]

On 2024-03-22 05:06, Tony Lindgren wrote:
[...]
> I can't reproduce this on qemu-system-sparc64, probably as it does not use
> the sunsab driver.
> 
> I noticed something though, I think we need to test for the port device
> instead for being runtime PM enabled.
> 
> Can you please test if the updated patch below make things work again?

Yes, with the below patch applied on top of 6.8 things are working.

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) || 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)