Re: [RFC PATCH v4 1/1] serial: core: Start managing serial controllers to enable runtime PM

[Ilpo Järvinen]

On Thu, 8 Dec 2022, Tony Lindgren wrote:

> * Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> [221208 09:12]:
> > On Wed, 7 Dec 2022, Tony Lindgren wrote:
> > > +	ret = serial_core_add_one_port(drv, port);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	mutex_lock(&port_mutex);
> > > +
> > > +	/* Inititalize a serial core controller device if needed */
> > > +	ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id);
> > > +	if (!ctrl_dev) {
> > > +		ctrl_dev = serial_core_ctrl_device_add(port);
> > > +		if (!ctrl_dev)
> > > +			goto err_remove_port;
> > > +		allocated = true;
> > > +	}
> > > +
> > > +	/* Initialize a serial core port device */
> > > +	ret = serial_core_port_device_add(ctrl_dev, port);
> > 
> > How is ->port_dev supposed to work here?
> > 
> > ->port_dev is not set until in serial_core_port_device_add() but you made
> > serial_core_add_one_port() call before that.
> 
> Hmm do you mean you want to call serial_core_add_one_port() later after
> serial_core_port_device_add()?
> 
> Or are you seeing some uninitialized use of port->port_dev (and not
> port->dev)?

With the other patch on top of this, yes, I did see uninitialized 
port->port_dev already in serial_core_add_one_port()->uart_configure_port().
While that could be solved by removing the pm_runtime_*() calls from 
there, I think it's a generic problem because after 
serial_core_add_one_port() the port can have anything happening on it, no?


-- 
 i.