Re: [PATCH] USB Elan FTDI: check for driver registration status

[Pete Zaitcev <zaitcev@redhat.com>]

On Tue, 27 Mar 2007 19:14:05 +0400, Cyrill Gorcunov <gorcunov@gmail.com> wrote:

> --- a/drivers/usb/misc/ftdi-elan.c
> @@ -2903,7 +2903,7 @@ static struct usb_driver ftdi_elan_driver = {
>  };
>  static int __init ftdi_elan_init(void)
>  {
> -        int result;
> +        int result = 0;

Why do you need this?

> @@ -2918,18 +2918,25 @@ static int __init ftdi_elan_init(void)
>  	if (!respond_queue)
>  		goto err3;
>          result = usb_register(&ftdi_elan_driver);
> -        if (result)
> +        if (result) {
>                  printk(KERN_ERR "usb_register failed. Error number %d\n",
>  		       result);
> +		goto err4;
> +	}
>          return result;
>  
> + err4:
> +	destroy_workqueue(respond_queue);
>   err3:

This is fine, although I do wish you wouldn't number the exception labels.
If anything is changed, someone might try to rearrange and renumber them
and that leads to bugs.

>   err1:
> -	printk(KERN_ERR "%s couldn't create workqueue\n", ftdi_elan_driver.name);
> -	return -ENOMEM;
> +	if (result == 0) {
> +		result = -ENOMEM;
> +		printk(KERN_ERR "%s couldn't create workqueue\n", ftdi_elan_driver.name);
> +	}
> +	return result;

What in the world is this supposed to do? Under what conditions can
result be zero here?

Personally, I would get rid of the printk. If your modprobe fails,
it's a good enough indication. Or at least, change the text to
something more neutral, like "unable to initialize (%d)" and print
the error code. It's not just about workqueues now.

-- Pete