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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 2D356C433ED for ; Wed, 19 May 2021 14:56:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 083E3610CD for ; Wed, 19 May 2021 14:56:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354935AbhESO6C (ORCPT ); Wed, 19 May 2021 10:58:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:49942 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347646AbhESO6C (ORCPT ); Wed, 19 May 2021 10:58:02 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E9F94610A8; Wed, 19 May 2021 14:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621436202; bh=jzfdsFACYB1jXMFuw3OU+MoiYpESakhRDHm2KhGQpgk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QQKY2yl6NXZDQCGVkReASRYXs+4z2cE1grbEstvCw7PgvvYbap/bwg3R57auIKud2 XdWEauAFPrejBMcGwsoBD9j2tlcYjj83pJrqtqTX9jpZJ6UOTQVnUt0dnvQ0cipCcy yjH31uX9bNG7wzK+S8jojZLor0+mcMZo0ahze6eY= Date: Wed, 19 May 2021 16:56:40 +0200 From: Greg Kroah-Hartman To: "Leizhen (ThunderTown)" Cc: Mathias Nyman , linux-usb Subject: Re: [PATCH 1/1] usb: xhci: remove unused variable 'len' in xhci_unmap_temp_buf() Message-ID: References: <20210519123304.7885-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, May 19, 2021 at 10:37:07PM +0800, Leizhen (ThunderTown) wrote: > > > On 2021/5/19 21:40, Leizhen (ThunderTown) wrote: > > > > > > On 2021/5/19 21:12, Greg Kroah-Hartman wrote: > >> On Wed, May 19, 2021 at 08:33:04PM +0800, Zhen Lei wrote: > >>> GCC reports the following warning with W=1: > >>> > >>> drivers/usb/host/xhci.c:1349:15: warning: > >>> variable 'len' set but not used [-Wunused-but-set-variable] > >>> 1349 | unsigned int len; > >>> | ^~~ > >>> > >>> This variable is not used, remove it to fix the warning. > >>> > >>> Reported-by: Hulk Robot > >>> Signed-off-by: Zhen Lei > >>> --- > >>> 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 27283654ca08..a75ed4a00997 100644 > >>> --- a/drivers/usb/host/xhci.c > >>> +++ b/drivers/usb/host/xhci.c > >>> @@ -1346,7 +1346,6 @@ 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; > >>> > >>> @@ -1362,7 +1361,7 @@ 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, > >>> + (void)sg_pcopy_from_buffer(urb->sg, urb->num_sgs, > >>> urb->transfer_buffer, > >>> buf_len, > >>> 0); > >>> -- > >>> 2.25.1 > >>> > >>> > >> > >> Wow, no. I keep telling you that this is not ok. Why keep sending > >> this? > > > > Sorry, I forgot to google it, someone already posted it. > > Hi, Greg Kroah-Hartman: > I've read your two exchange emails from https://patchwork.kernel.org/project/linux-usb/patch/20210306120644.74406-1-zhangkun4jr@163.com/#24019765 > How about just give a warning when the copy is not complete? This W=1 warning will probably be detected by someone else. Handle the error properly. Just spitting a message to a user where they can't do anything about it does not seems like the correct solution to me, would you want the kernel to do that? thanks, greg k-h