Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030354AbcJ0WC5 (ORCPT ); Thu, 27 Oct 2016 18:02:57 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:35539 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934551AbcJ0WCx (ORCPT ); Thu, 27 Oct 2016 18:02:53 -0400 From: Brian Norris To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, , Dmitry Torokhov , Brian Norris Subject: [RFC PATCH] usb: core: correct usb_get_dev() documentation Date: Thu, 27 Oct 2016 15:02:30 -0700 Message-Id: <1477605750-30117-1-git-send-email-computersforpeace@gmail.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1599 Lines: 37 In reading through a USB interface driver, I noticed that it called usb_{get,put}_dev() in its probe() and disconnect() methods. This seemed unnecessary, but a look at the comments here matched the usage. USB interface devices seem to be well covered by the parent/child relationship of the device model, and so it should be unnecessary for a child device to grab a refcount on its parent device. Signed-off-by: Brian Norris --- This reflects my understanding (and testing), as well as the majority of usage -- there are *very* few interface drivers that actually call usb_get_dev(). If I'm wrong, please feel free to tell me so! But I thought patching the documentation would be the best way to solicit a response :) drivers/usb/core/usb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 592151461017..0ba7e070f04e 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -539,9 +539,9 @@ EXPORT_SYMBOL_GPL(usb_alloc_dev); * * Each live reference to a device should be refcounted. * - * Drivers for USB interfaces should normally record such references in - * their probe() methods, when they bind to an interface, and release - * them by calling usb_put_dev(), in their disconnect() methods. + * The device driver core automatically handles this refcounting for USB + * interface drivers, but this API can be used for non-parent/child + * relationships. * * Return: A pointer to the device with the incremented reference counter. */ -- 2.8.0.rc3.226.g39d4020