On Thu, Apr 11, 2024 at 08:58:45AM +0300, Tony Lindgren wrote:
> We are seeing start_tx being called after port shutdown as noted by Jiri.
> This happens because we are missing the startup and shutdown related
> functions for the serial base port.
>
> Let's fix the issue by adding startup and shutdown functions for the
> serial base port to block tx flushing for the serial base port when the
> port is not in use.
I'm going to test this later today, meanwhile some comments below.
...
> +out_base_port_startup:
> + uport = uart_port_check(state);
> + if (!uport)
> + return -EIO;
> +
> + serial_base_port_startup(uport);
So, we call this even on uninitialised TTY. Is it okay?
> + return 0;
> }
...
> if (tty)
> set_bit(TTY_IO_ERROR, &tty->flags);
> + if (uport)
> + serial_base_port_shutdown(uport);
Why not to call it after the below check to be reverse-symmetrical with startup?
> if (tty_port_initialized(port)) {
> tty_port_set_initialized(port, false);
>
...
> /* Flush any pending TX for the port */
> uart_port_lock_irqsave(port, &flags);
> + if (!port_dev->tx_enabled)
> + goto unlock;
Can't this be integrated into...
> if (__serial_port_busy(port))
...this call?
> port->ops->start_tx(port);
> +
> +unlock:
> uart_port_unlock_irqrestore(port, flags);
>
...
> uart_port_lock_irqsave(port, &flags);
> + if (!port_dev->tx_enabled) {
> + uart_port_unlock_irqrestore(port, flags);
> + return 0;
> + }
> +
> busy = __serial_port_busy(port);
> if (busy)
> port->ops->start_tx(port);
Ditto.
--
With Best Regards,
Andy Shevchenko
