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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 262C3C2BA2B for ; Fri, 17 Apr 2020 00:41:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAFA620771 for ; Fri, 17 Apr 2020 00:41:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fYAgdfU8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728177AbgDQAlY (ORCPT ); Thu, 16 Apr 2020 20:41:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725862AbgDQAlX (ORCPT ); Thu, 16 Apr 2020 20:41:23 -0400 Received: from mail-ot1-x32c.google.com (mail-ot1-x32c.google.com [IPv6:2607:f8b0:4864:20::32c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAE9EC061A0C for ; Thu, 16 Apr 2020 17:41:22 -0700 (PDT) Received: by mail-ot1-x32c.google.com with SMTP id c3so177560otp.8 for ; Thu, 16 Apr 2020 17:41:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:subject:message-id:mime-version:content-disposition :user-agent; bh=jaxzzAGgt9b40w7dm+PLMrbiJc5E7EIOZfTpiPld5dU=; b=fYAgdfU897RkYG2bz88QgkywyCdCuxr3sjiRrrGJho9CBD3hX0vK/A3eDW/38UfWwD aXvPWzKgW6AupBrY93Ydgahlyg19WTUuuVG1ikla1ySXad3Y69k8q+RqGk1SAR0KIMPN NlsvIDzl6rTA9CUkm/HHrvOPYvgB0VJA4kgm7FnKe6/FvC1F51Ca1uhsWnpmXEPk8wLR KQQnnj6agUopxhmugxEUoekc/wJ5weIKcVeYDo4ZCIXTUWD6yNBQbRrquTy3Yu0RLX/X xlyxz+kruLpgu5TKROS4alAwmG3kCJhW5SLC+RFFSxl54UXcC2S2nBSWmgOZBlu/Y/ZQ wV0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-disposition:user-agent; bh=jaxzzAGgt9b40w7dm+PLMrbiJc5E7EIOZfTpiPld5dU=; b=i3n7BR0HeBybnvDbJUrC2v6maq77nrLbCHthE49f3DEuSauommy9JeoJNYuFiTC+Hy Z+fznOWIMDMNK4xPO4Fxe6TVIUYuqsl79oaVsOOHcbqGMEeMQXpdE/A6tgdwndVABmk6 hdKYXUzz+us9VD3osR+ND8jj8WcM8GfHk1eXDaZZjQkJe+4pk6JOkFtu6vC8dsSfdPFg OUnVawXvAR2zmp7OoAFxNEj/aIyZ5sn5jaZ+gWgUUDoewg6C4QLVGW8GIJZNTy2uoTUL Cx/hll77jO3UVMRdqmfTPU69cmXkc0mF2nbyvIyzNFTuPponxh34lTQlJ6KviQ0i4QrO lxog== X-Gm-Message-State: AGi0Pub9ZKIrlUucr+lfxprc1phKs89uPrkZqkDy0wkHh1RzkaLfsNLi OkAEt8OMDMUWSbdqVpV/5xEVsvQN X-Google-Smtp-Source: APiQypJVeQgCgJIBueRDX1wphwvgGeLR4ifSOAi2+gznZ/lld7E11OqmbCDVoqNVFFfmteCdiP7q+w== X-Received: by 2002:a9d:a55:: with SMTP id 79mr659666otg.295.1587084081906; Thu, 16 Apr 2020 17:41:21 -0700 (PDT) Received: from ubuntu-s3-xlarge-x86 ([2604:1380:4111:8b00::3]) by smtp.gmail.com with ESMTPSA id i21sm5809655ooe.26.2020.04.16.17.41.21 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 16 Apr 2020 17:41:21 -0700 (PDT) Date: Thu, 16 Apr 2020 17:41:20 -0700 From: Nathan Chancellor To: netdev@vger.kernel.org, clang-built-linux@googlegroups.com Subject: -Wconstant-conversion in drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Message-ID: <20200417004120.GA18080@ubuntu-s3-xlarge-x86> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi all, I was building s390 allyesconfig with clang and came across a curious warning: drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:580:41: warning: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551584 to -32 [-Wconstant-conversion] mvpp2_pools[MVPP2_BM_SHORT].pkt_size = MVPP2_BM_SHORT_PKT_SIZE; ~ ^~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2.h:699:33: note: expanded from macro 'MVPP2_BM_SHORT_PKT_SIZE' #define MVPP2_BM_SHORT_PKT_SIZE MVPP2_RX_MAX_PKT_SIZE(MVPP2_BM_SHORT_FRAME_SIZE) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2.h:634:30: note: expanded from macro 'MVPP2_RX_MAX_PKT_SIZE' ((total_size) - NET_SKB_PAD - MVPP2_SKB_SHINFO_SIZE) ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ 1 warning generated. As far as I understand it, the warning comes from the fact that MVPP2_BM_SHORT_FRAME_SIZE is treated as size_t because MVPP2_SKB_SHINFO_SIZE ultimately calls ALIGN with sizeof(struct skb_shared_info), which has typeof called on it. The implicit conversion probably is fine but it would be nice to take care of the warning. I am not sure what would be the best way to do that would be though. An explicit cast would take care of it, maybe in MVPP2_SKB_SHINFO_SIZE since the actual value I see is 320, which is able to be fit into type int easily. Any comments would be appreciated, there does not appear to be a dedicated maintainer of this driver according to get_maintainer.pl. Cheers, Nathan