On Thu, Feb 17, 2022 at 10:25:02AM -0500, Alan Stern wrote: > On Thu, Feb 17, 2022 at 11:04:59AM +0300, Dan Carpenter wrote: > > Salah sent a bunch of these. The reasoning was explained in this email. > > > > https://www.spinics.net/lists/kernel/msg4026672.html > > > > When he resent the patch, Greg said that taking the reference wasn't > > needed so the patch wasn't applied. (Also it had the same reference > > leak so that's a second reason it wasn't applied). > > Indeed, the kerneldoc for usb_get_intf() does say that each reference > held by a driver must be refcounted. And there's nothing wrong with > doing that, _provided_ you do it correctly. > > But if you know the extra refcount will never be needed (because the > reference will be dropped before the usb_interface in question is > removed), fiddling with the reference count is unnecessary. I guess > whether or not to do it could be considered a matter of taste. > > On the other hand, it wouldn't hurt to update the kerneldoc for > usb_get_intf() (and usb_get_dev() also). We could point out that if a > driver does not access the usb_interface structure after its disconnect > routine returns, incrementing the refcount isn't mandatory. That would be good to add to prevent this type of confusion in the future. thanks, greg k-h
