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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 0881ACA9EA9 for ; Fri, 18 Oct 2019 18:52:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DBEF5222C5 for ; Fri, 18 Oct 2019 18:52:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571424746; bh=OqPa3AhbNUgoijvZsXeWlvCHx7lRFGDH4OJ29A3bdhg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=TA95pyvIla1zdqKLa8zX27NKYXdyYh532sOECZ+wP3/sMGkJXUwaYNw8TQTsMqSQy wlOcxPxohCz51HWE9U7fn71kgJMhVmLpzatyC7zzurnXOv68JkFvsk0Ixw71cpnPLM 6UbZ5VL475tGs3hMXuvQNAES9kc68Qi0Lth5uzeA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439939AbfJRSw0 (ORCPT ); Fri, 18 Oct 2019 14:52:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:55186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439902AbfJRSw0 (ORCPT ); Fri, 18 Oct 2019 14:52:26 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 9BE5620640; Fri, 18 Oct 2019 18:52:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571424745; bh=OqPa3AhbNUgoijvZsXeWlvCHx7lRFGDH4OJ29A3bdhg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Fb4rem9ugVmK91zACy5BmV8YBx0iNsVsPa7GZaV7wUqCzftCq+8WP2vmj2FGbVUEH 0/LJVksSg25WYHHWRZAlou7Dp5AHcqH7eoEdLVrIDeb7DknHr1W2aDM9XqYmSUiynm pLsvt+Jm/AoY2P4zWsRykNQ46CGCkAF3Uh3Rl448= Date: Fri, 18 Oct 2019 19:52:20 +0100 From: Jonathan Cameron To: Tomasz Duszynski Cc: linux-iio@vger.kernel.org, Jonathan Cameron Subject: Re: [PATCH] iio: chemical: sps30: Explicity truncate constant by masking Message-ID: <20191018195220.084d382c@archlinux> In-Reply-To: <20191017164112.GA5100@arch> References: <20191013095515.1438147-1-jic23@kernel.org> <20191017164112.GA5100@arch> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Thu, 17 Oct 2019 18:41:12 +0200 Tomasz Duszynski wrote: > On Sun, Oct 13, 2019 at 10:55:15AM +0100, jic23@kernel.org wrote: > > From: Jonathan Cameron > > > > When breaking up a constant to write to two 8 bit registers > > it isn't obvious to sparse that it was intentional. > > > > CHECK drivers/iio/chemical/sps30.c > > drivers/iio/chemical/sps30.c:120:30: warning: cast truncates bits from constant value (8004 becomes 4) > > > > So in the interests of minimising noisy warnings, let us add > > a mask. > > > > Signed-off-by: Jonathan Cameron > > Cc: Tomasz Duszynski > > --- > > drivers/iio/chemical/sps30.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c > > index edbb956e81e8..acb9f8ecbb3d 100644 > > --- a/drivers/iio/chemical/sps30.c > > +++ b/drivers/iio/chemical/sps30.c > > @@ -117,7 +117,7 @@ static int sps30_do_cmd(struct sps30_state *state, u16 cmd, u8 *data, int size) > > break; > > case SPS30_READ_AUTO_CLEANING_PERIOD: > > buf[0] = SPS30_AUTO_CLEANING_PERIOD >> 8; > > - buf[1] = (u8)SPS30_AUTO_CLEANING_PERIOD; > > + buf[1] = (u8)(SPS30_AUTO_CLEANING_PERIOD & 0xff); > > /* fall through */ > > case SPS30_READ_DATA_READY_FLAG: > > case SPS30_READ_DATA: > > -- > > 2.23.0 > > > > Thanks for catching this. > Acked-by: Tomasz Duszynski Applied. Thanks, Jonathan