Re: [PATCH] Minor change to platform_device_register_simple prototype

[Jean Delvare <khali@linux-fr.org>]

Hi Dmirty, Russell, Greg,

> On 12/7/05, Greg KH <greg@kroah.com> wrote:
> > So, if you had _del, would it work easier for you?  I just objected to
> > it if it wasn't necessary.  I didn't want to add functions that aren't
> > used by anyone, but if is needed, I don't see a problem with it.
> 
> Yes, the I can just write:
> 
>         ...
>         err = platform_driver_register(&i8042_driver);
>         if (err)
>                 goto err_controller_cleanup;
> 
>         i8042_platform_device = platform_device_alloc("i8042", -1);
>         if (!i8042_platform_device) {
>                 err = -ENOMEM;
>                 goto err_unregister_driver;
>         }
> 
>         err = platform_device_add(i8042_platform_device);
>         if (err)
>                 goto err_free_device;
>         ...
> 
>         if (!have_ports) {
>                 err = -ENODEV;
>                 goto err_delete_device;
>         }
> 
>         mod_timer(&i8042_timer, jiffies + I8042_POLL_PERIOD);
>         return 0;
> 
>  err_delete_device:
>         platform_device_del(i8042_platform_device);
>  err_free_device:
>         platform_device_put(i8042_platform_device);
>  err_unregister_driver:
>         platform_driver_unregister(&i8042_driver);
>  ....
> 
> As you can see - single cleanup path..

I second Dmitry's request here. I can't seem to possibly build a valid
error path during device registration with the current API. Having
platform_device_del() would make it possible.

BTW, doesn't this suggest that the error path in
platform_device_register_simple() is currently broken as well? If
platform_device_add() fails therein, I take it that the resources
previously allocated by platform_device_add_resources() will never be
freed.

-- 
Jean Delvare