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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 28715C43381 for ; Sun, 7 Mar 2021 01:19:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA26D64E02 for ; Sun, 7 Mar 2021 01:19:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230051AbhCGBPi (ORCPT ); Sat, 6 Mar 2021 20:15:38 -0500 Received: from m12-16.163.com ([220.181.12.16]:52614 "EHLO m12-16.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229801AbhCGBPZ (ORCPT ); Sat, 6 Mar 2021 20:15:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Subject:From:Message-ID:Date:MIME-Version; bh=0PQOv 2/hQx64gECYG05guj9Z2VJN6/F73EZBhLsxdYQ=; b=ma60aVLE7woVTmjlokm8V Usq2vijoW7yYkjAqyPaVvyNRHsoZ0wUuhaGyOto2SAV40b2sK66yfCIfCWBB5OuX vyg8pMrYBLbefbixCHhkirzvPuoCDrgslsmzbyhgJjbd1LT4wj2fj/msHWiDfaoU 8yYYCmGr0n2EWtvkJGFETE= Received: from [192.168.31.187] (unknown [36.170.36.204]) by smtp12 (Coremail) with SMTP id EMCowAAnKk7yKERgk+T+fA--.43990S2; Sun, 07 Mar 2021 09:14:27 +0800 (CST) Subject: Re: [PATCH] xhci: Remove unused value len from xhci_unmap_temp_buf To: Greg Kroah-Hartman Cc: Mathias Nyman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Zhang Kun References: <20210306120644.74406-1-zhangkun4jr@163.com> From: Zhangkun Message-ID: <3ad81fd6-e88e-f55b-fe82-ac7804bc354c@163.com> Date: Sun, 7 Mar 2021 09:14:26 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CM-TRANSID: EMCowAAnKk7yKERgk+T+fA--.43990S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7Zr48KFWUKryruFy3GF18AFb_yoW8Wr47pF s8Ka1YkFs5trZFkasrZanavFyrta1xJrykKrWIya45XFZxCFnIqF97WFyfKrnxWr4fGr1I vF4UXayrWw1Dua7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07bc4EiUUUUU= X-Originating-IP: [36.170.36.204] X-CM-SenderInfo: x2kd0whnxqkyru6rljoofrz/1tbirAVOtVr7sfJfFgAAs5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/7/21 12:25 AM, Greg Kroah-Hartman wrote: > On Sat, Mar 06, 2021 at 08:06:44PM +0800, zhangkun4jr@163.com wrote: >> From: Zhang Kun >> >> The value assigned to len by sg_pcopy_from_buffer() never used for >> anything, so remove it. >> >> Signed-off-by: Zhang Kun >> --- >> drivers/usb/host/xhci.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c >> index bd27bd670104..6ebda89d476c 100644 >> --- a/drivers/usb/host/xhci.c >> +++ b/drivers/usb/host/xhci.c >> @@ -1335,7 +1335,6 @@ static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd, >> >> static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb) >> { >> - unsigned int len; >> unsigned int buf_len; >> enum dma_data_direction dir; >> >> @@ -1351,7 +1350,7 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb) >> dir); >> >> if (usb_urb_dir_in(urb)) >> - len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs, >> + sg_pcopy_from_buffer(urb->sg, urb->num_sgs, >> urb->transfer_buffer, >> buf_len, >> 0); > > SHouldn't this be checked instead of ignored? > Hi, Greg. Considering your tips I checked sg_pcopy_from_buffer(). it copys data from urb->transfer_buffer to urb->sg, and only returns 0 or the 'number of copied bytes', and seems to has no other exception branchs that need to be checked. So I think it should be ingnored. It may also be that I missed something, if that's the case, please correct me. Thanks, Zhang