From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55345C04EB8 for ; Mon, 10 Dec 2018 20:06:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1DBED2082F for ; Mon, 10 Dec 2018 20:06:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DBED2082F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=rowland.harvard.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729786AbeLJUGN (ORCPT ); Mon, 10 Dec 2018 15:06:13 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:33786 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726912AbeLJUGM (ORCPT ); Mon, 10 Dec 2018 15:06:12 -0500 Received: (qmail 5481 invoked by uid 2102); 10 Dec 2018 15:06:11 -0500 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 10 Dec 2018 15:06:11 -0500 Date: Mon, 10 Dec 2018 15:06:11 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Suwan Kim cc: gregkh@linuxfoundation.org, , , , , Subject: Re: [PATCH] usb: core: Remove unnecessary memset() In-Reply-To: <20181204143143.8407-1-suwan.kim027@gmail.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 4 Dec 2018, Suwan Kim wrote: > register_root_hub() calls memset() setting usb_dev->bus->devmap. > devicemap to 0 during hcd probe function (usb_hcd_pci_probe). But > in previous function which is also the procedure of usb_hcd_pci_probe(), > usb_bus_init() already initialized bus->devmap calling memset(). > Furthermore, register_root_hub() is called only once in kernel. > So, calling memset() which resets usb_bus->devmap.devicemap in > register_root_hub() is redundant. > > Signed-off-by: Suwan Kim > --- > drivers/usb/core/hcd.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c > index 487025d31d44..015b126ce455 100644 > --- a/drivers/usb/core/hcd.c > +++ b/drivers/usb/core/hcd.c > @@ -1074,8 +1074,6 @@ static int register_root_hub(struct usb_hcd *hcd) > > usb_dev->devnum = devnum; > usb_dev->bus->devnum_next = devnum + 1; > - memset (&usb_dev->bus->devmap.devicemap, 0, > - sizeof usb_dev->bus->devmap.devicemap); > set_bit (devnum, usb_dev->bus->devmap.devicemap); > usb_set_device_state(usb_dev, USB_STATE_ADDRESS); Acked-by: Alan Stern