Re: [PATCH 04/11] remove usb_interface pointer

[Stefani Seibold]

Am Donnerstag, den 07.06.2012, 11:27 -0400 schrieb Alan Stern:
> On Thu, 7 Jun 2012, Stefani Seibold wrote:
> > I think it will be needed, since usb core will decrement the reference
> > when the device go away.
> 
> But before it decrements the reference, it will unbind the driver.  As 
> long as usb-skeleton is careful not to access the device or the 
> interface after the disconnect routine returns, it doesn't need to keep 
> a reference.
> 
> >  Lock every access to the usb core if a tedious
> > thing and will waste a lot of code.
> 
> With proper design, it's not necessary to lock every access.
> > 
> > BTW: An interface have no reference count.
> 
> Sure it does.  Look at the definitions of usb_get_intf() and 
> usb_put_intf() in drivers/usb/core/usb.c.
> 

That what i am looking for. If we do an usb_get_intf() in the
skel_probe() function and an usb_put_intf() in skel_delete() function at
the end, then it should be save to access the usb_device pointer by
interface_to_usbdev() in the skel_delete() function. Right?

Greetings,
Stefani


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