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=unavailable 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 D52E0C4708A for ; Thu, 27 May 2021 09:50:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0A8F613F1 for ; Thu, 27 May 2021 09:50:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235976AbhE0Jvq (ORCPT ); Thu, 27 May 2021 05:51:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:42400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235809AbhE0Jvo (ORCPT ); Thu, 27 May 2021 05:51:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1CF87613F0; Thu, 27 May 2021 09:50:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622109010; bh=cmBGcT0eRQCBifI792Q3HjHvjS5nOyNVd0fvq4gyHIc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VXLkNE34YcBekZ+KiAEGlrxt8hnaZJWlF1hJj67aTiFuVJbWsub9+XFUcD84c9K2W UekIIAdHGPa9ToZWZ/gJguTBuoXKysZMnOT16ChOMEJXfiK05oL8F7O0stHUxldTiZ 2I+z2JsMRh8dhs8Uoa26Tx8L7iWQsIPirpXphd+8= Date: Thu, 27 May 2021 11:50:07 +0200 From: Greg Kroah-Hartman To: Mathias Nyman Cc: Lee Jones , linux-kernel@vger.kernel.org, Mathias Nyman , linux-usb@vger.kernel.org Subject: Re: [PATCH 17/24] usb: host: xhci: Remove unused variable 'len' Message-ID: References: <20210526130037.856068-1-lee.jones@linaro.org> <20210526130037.856068-18-lee.jones@linaro.org> <20210527081609.GF543307@dell> <5958f870-1834-3132-a729-2b26a84349ea@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5958f870-1834-3132-a729-2b26a84349ea@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 27, 2021 at 12:23:24PM +0300, Mathias Nyman wrote: > On 27.5.2021 11.16, Lee Jones wrote: > > On Thu, 27 May 2021, Greg Kroah-Hartman wrote: > > > >> On Wed, May 26, 2021 at 02:00:30PM +0100, Lee Jones wrote: > >>> Fixes the following W=1 kernel build warning(s): > >>> > >>> drivers/usb/host/xhci.c: In function ‘xhci_unmap_temp_buf’: > >>> drivers/usb/host/xhci.c:1349:15: warning: variable ‘len’ set but not used [-Wunused-but-set-variable] > >>> > >>> Cc: Mathias Nyman > >>> Cc: Greg Kroah-Hartman > >>> Cc: linux-usb@vger.kernel.org > >>> Signed-off-by: Lee Jones > >>> --- > >>> drivers/usb/host/xhci.c | 9 ++++----- > >>> 1 file changed, 4 insertions(+), 5 deletions(-) > >>> > >>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > >>> index 27283654ca080..ac2a7d4288883 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; > >>> > >>> @@ -1362,10 +1361,10 @@ 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, > >>> - urb->transfer_buffer, > >>> - buf_len, > >>> - 0); > >>> + sg_pcopy_from_buffer(urb->sg, urb->num_sgs, > >>> + urb->transfer_buffer, > >>> + buf_len, > >>> + 0); > >> > >> Sorry, but no, I keep rejecting this over and over, it needs to handle > >> the error handling properly and not paper over it like this :( > > > > Will fix. > > > >> All the bots keep tripping up on it, you are not alone. > > > > This is getting a lot of attention. Something like this should fix it: > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > index 27283654ca08..306ab81421fd 100644 > --- a/drivers/usb/host/xhci.c > +++ b/drivers/usb/host/xhci.c > @@ -1361,12 +1361,16 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb) > urb->transfer_buffer_length, > dir); > > - if (usb_urb_dir_in(urb)) > + if (usb_urb_dir_in(urb)) { > len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs, > urb->transfer_buffer, > buf_len, > 0); > - > + if (len != buf_len) { > + xhci_dbg(xhci, "Copy from tmp buf to urb sg list failed\n"); > + urb->actual_length = len; > + } > + } > urb->transfer_flags &= ~URB_DMA_MAP_SINGLE; > kfree(urb->transfer_buffer); > urb->transfer_buffer = NULL; > > urb->actual_length is now properly set. > The debug level message will help me find the cause if we ever need > to debug oddly behaving devices. > > Note this is a very rarly taken codepath for quirky xHC harware that > can't handle a specific sequence of buffer lengths queued. > > I can write a proper commit message and push this forward That looks good, I kept waiting for one of the people who kept trying to report "build warning fixes" to do it right, but I'll gladly take it from you as well :) thanks, greg k-h