Re: [PATCH 20/29] tty: srmcons: fix retval from srmcons_init()

[Jiri Slaby]

On 20. 02. 25, 22:48, Magnus Lindholm wrote:
> I've applied and verified this patch on an Alphaserver ES40 with
> serial console.
>
> Regarding the future use of label err_free_drv, is the intention to
> use it to break out early if tty_alloc_driver() fails?

...

> > +       if (!srm_is_registered_console)
> > +               return -ENODEV;
> > +
> > +       driver = tty_alloc_driver(MAX_SRM_CONSOLE_DEVICES, 0);
> > +       if (IS_ERR(driver))
> > +               return PTR_ERR(driver);
> > +
> > +       tty_port_init(&srmcons_singleton.port);
> > +
> > +       driver->driver_name = "srm";
> > +       driver->name = "srm";
> > +       driver->major = 0;      /* dynamic */
> > +       driver->minor_start = 0;
> > +       driver->type = TTY_DRIVER_TYPE_SYSTEM;
> > +       driver->subtype = SYSTEM_TYPE_SYSCONS;
> > +       driver->init_termios = tty_std_termios;
> > +       tty_set_operations(driver, &srmcons_ops);
> > +       tty_port_link_device(&srmcons_singleton.port, driver, 0);

I plan on removing tty_port_link_device() as it was a temporary aid. 
Yay, for 13 years! (commit 2cb4ca0208722).

> > +       err = tty_register_driver(driver);
> > +       if (err)
> > +               goto err_free_drv;

Instead, the idea is to properly tty_port_register_device() after 
tty_register_driver() instead. And that can fail. So is fail path reuses 
err_free_drv (and adds tty_unregister_driver() on top).

> > +
> > +       srmcons_driver = driver;
> > +
> > +       return 0;
> > +err_free_drv:
> > +       tty_driver_kref_put(driver);
> > +       tty_port_destroy(&srmcons_singleton.port);
> > +
> > +       return err;

thanks,
--
js
suse labs