Re: [PATCH 04/11] remove usb_interface pointer

[Alan Stern]

On Thu, 7 Jun 2012, Stefani Seibold wrote:

> I tried to implement your idea to kick away the usb_device pointer, but
> i think it is impossible. The skel_delete() function needs the
> usb_device pointer for calling usb_put, which is called from
> skel_disconnect() or skel_release().
  
Does skel_delete() really need to call usb_put_dev()?  I suspect that  
the driver doesn't need to take a reference to either the device or the
interface.
  
> A call of interface_to_usbdev(dev->intf) results in a udev pointer, but
> this pointer is only valid if it was called trough kref_put() from
> skel_disconnect().
> 
> For an already opened devices, the call will come from skel_release()
> and in this case the interface pointer could be already owned by an
> other driver and no more longer handle by the skeleton driver.
> 
> So i think we need both.

If skel_delete is changed then we don't need the usb_device pointer.

Alan Stern

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