Re: RFC: remove usb_device pointer from usb_skeleton.c
From: Alan Stern
Date: Fri Jun 08 2012 - 09:46:01 EST
On Fri, 8 Jun 2012, Stefani Seibold wrote:
> Hi,
>
> what do you think about this solution for removing the usb_device
> pointer from the struct usb_skel in the usb_skeleton driver?
There's nothing wrong with keeping the pointer there. Why do you want
to remove it?
> @@ -73,9 +73,12 @@ static struct usb_driver skel_driver;
> static void skel_delete(struct kref *kref)
> {
> struct usb_skel *dev = to_skel_dev(kref);
> + struct usb_interface *interface = dev->interface;
> + struct usb_device *udev = usb_get_dev(interface_to_usbdev(interface));
>
> usb_free_urb(dev->bulk_in_urb);
> - usb_put_dev(dev->udev);
> + usb_put_dev(udev);
On the other hand, this usb_put_dev call is useless. Why do you want
to keep it?
> + usb_put_intf(interface);
If you get rid of the usb_put_dev then this call is also useless.
> kfree(dev->bulk_in_buffer);
> kfree(dev);
> }
> @@ -128,7 +131,7 @@ static int skel_release(struct inode *inode, struct file *file)
>
> /* allow the device to be autosuspended */
> mutex_lock(&dev->io_mutex);
> - if (dev->interface)
> + if (dev->connected)
There's nothing really wrong with adding a "disconnected" flag. But
setting dev->interface to NULL works just as well, in my opinion. It's
a matter of taste.
Alan Stern
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