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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 DBB07C2BA19 for ; Tue, 14 Apr 2020 11:56:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B45C220732 for ; Tue, 14 Apr 2020 11:56:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="cMRgeWs/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439733AbgDNL4k (ORCPT ); Tue, 14 Apr 2020 07:56:40 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:46136 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439721AbgDNL4X (ORCPT ); Tue, 14 Apr 2020 07:56:23 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03EBmdm8015076; Tue, 14 Apr 2020 11:56:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=FHLWQFpis8qC0ost0GJpkrUK3UmvMx3TtVVZsTxGv0U=; b=cMRgeWs/2IvX4EUo3a/Lvzs1QAww3YiHVsDUnb7nUtGaieQCbJ+cDRNcPdqqreGvcvNY iy6hcoXcGVx0N7b8HdF6eaywud0fc1sPgEx66gnVpMlwy0qj74K2MEdbBiSm8szKsdBC tOUMKetRp4kjYsB0NoHy+Djxsj/nzGPQHSIn3NmAnkVuGeDYGaD/ORbZtyA1lFkn/I3u mcb4s7GhnSXvYe0U0qfdcYeY1jUuj/nzAo5rlQAotADyVg6Jv3nlumq7F/l1/cs6AEBh 0M6blAkcalb8/xm1hs9JdKz7n7lJe4VxRQURar1Uh/ufc+JfMmpfXGVWrjbUgZLrlLH3 2A== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 30b5ar42t8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 14 Apr 2020 11:56:16 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03EBliJY083552; Tue, 14 Apr 2020 11:56:15 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 30bqchf63b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 14 Apr 2020 11:56:15 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 03EBuCNt014251; Tue, 14 Apr 2020 11:56:14 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 14 Apr 2020 04:56:12 -0700 Date: Tue, 14 Apr 2020 14:56:05 +0300 From: Dan Carpenter To: Ivan Safonov Cc: Nishka Dasgupta , Larry Finger , Greg Kroah-Hartman , Michael Straube , devel@driverdev.osuosl.org, "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 5/8] staging: rtl8188eu: Remove function rtw_modular64() Message-ID: <20200414115604.GF1163@kadam> References: <20190712071746.2474-5-nishkadg.linux@gmail.com> <66fb1e37-107e-54f4-4986-ca4e4bb99d2d@yandex.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <66fb1e37-107e-54f4-4986-ca4e4bb99d2d@yandex.ru> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9590 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=18 mlxlogscore=822 bulkscore=0 malwarescore=0 phishscore=0 mlxscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004140099 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9590 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 impostorscore=0 clxscore=1011 priorityscore=1501 malwarescore=0 phishscore=0 spamscore=0 mlxlogscore=890 suspectscore=18 adultscore=0 mlxscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004140099 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 12, 2020 at 04:34:08PM +0300, Ivan Safonov wrote: > > Remove function rtw_modular64 as all it does is call do_div. > > This is wrong. Macro do_div(x, y) change first argument x, but > rtw_modular64(x, y) preserve it. > > > + tsf = pmlmeext->TSFValue - do_div(pmlmeext->TSFValue, (pmlmeinfo->bcn_interval*1024)) - 1024; /* us */ > > rounddown(pmlmeext->TSFValue, pmlmeinfo->bcn_interval * 1024) - 1024 > is a better replacement for You're absolutely correct that the patch is buggy, but I'm not sure that rounddown() is what we want. rtw_modular64() took the MOD of x. So it should be something like: tsf = pmlmeext->TSFValue - (pmlmeext->TSFValue % (pmlmeinfo->bcn_interval * 1024)) - 1024; /* us */ But what the heck is that even??? If pmlmeinfo->bcn_interval is zero or one then the subtraction ends up giving us a negative. regards, dan carpenter