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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 3B888C3A589 for ; Tue, 20 Aug 2019 11:38:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E939C214DA for ; Tue, 20 Aug 2019 11:38:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566301091; bh=AciBUPAu82B05NczuPVQfEs6Tmsa+FH1VhYXzvvho/Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=OY3Tj7bejHlntf0qEFfCLwUKqCNuMJOgLjaWwfvvS+3S/xFnE3wjFBnz7qSIX8kro J7Y23LK5bSRFfCZ4wPcIb6++uJIDBbv9mw2XwopP4JfsaH5UUxMZ2ZP+4AvCxcueON E30DrsB6LMjMn1a8G31GwmH0us7PsQvuCfb1MwgQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729541AbfHTLiK (ORCPT ); Tue, 20 Aug 2019 07:38:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:45362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729421AbfHTLiK (ORCPT ); Tue, 20 Aug 2019 07:38:10 -0400 Received: from localhost (unknown [106.201.62.126]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CEC2620C01; Tue, 20 Aug 2019 11:38:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566301089; bh=AciBUPAu82B05NczuPVQfEs6Tmsa+FH1VhYXzvvho/Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zF8X7uV6Hg53HHI9pdfroR8XXMuq0Q6El9vcBuwaMcYwes4jW79F273FbuFLKZ0iq VSHWNVD/sWh4lPihmtX9tRHsunPmkp+6VDLFIP3k8cUJ5Vo0LkvLEiSV2RYrtLe8RG GmQTd9h7GGcqNAXS5fcOTA236lOWgYk/KE/7N7ck= Date: Tue, 20 Aug 2019 17:06:57 +0530 From: Vinod Koul To: Nathan Huckleberry Cc: dan.j.williams@intel.com, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH v2] dmaengine: mv_xor_v2: Fix -Wshift-negative-value Message-ID: <20190820113657.GV12733@vkoul-mobl.Dlink> References: <20190813173448.109859-1-nhuck@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190813173448.109859-1-nhuck@google.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 13-08-19, 10:34, Nathan Huckleberry wrote: > Clang produces the following warning > > drivers/dma/mv_xor_v2.c:264:40: warning: shifting a negative signed value > is undefined [-Wshift-negative-value] > reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << > MV_XOR_V2_DMA_IMSG_THRD_SHIFT); > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ > drivers/dma/mv_xor_v2.c:271:46: warning: shifting a negative signed value > is undefined [-Wshift-negative-value] > reg &= (~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK << > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ > > Upon further investigation MV_XOR_V2_DMA_IMSG_THRD_SHIFT and > MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT are both 0. Since shifting by 0 does > nothing, these variables can be removed. Applied, thanks -- ~Vinod