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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A40BC433EF for ; Thu, 10 Feb 2022 12:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241464AbiBJMQg (ORCPT ); Thu, 10 Feb 2022 07:16:36 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:34052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232947AbiBJMQg (ORCPT ); Thu, 10 Feb 2022 07:16:36 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F7F1116D; Thu, 10 Feb 2022 04:16:37 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3965EB82426; Thu, 10 Feb 2022 12:16:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60A27C004E1; Thu, 10 Feb 2022 12:16:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1644495395; bh=EtUqhE4EZ9tdkev8HxZrxLizLPpEiWHGvcR5Smiyjcc=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=r1O7Xl728X6lQMXclEDmP1qt51soJ34yuAs975UmUN1mwAwIz8lI8E5ZDMW4x9r0k uzcOjB40XXO7jYXPE97bky+6IS4ffDfvh9ikj191yBlRPPo83CvZd/fsLwDKxSdeKq 9r/v13pF/CwrXDrcSbLX1B9vwEQgLvf4Jg0sXF0Yq0YSHlUDjHmxxIiyKs06iXFJnC tiPliv7heN7wLogCp8zs6JYpCg6zK4u2G/EkAeZSr/6J/arUMgXgeKDRxnhdxjazfl VHsWlsWJLLxWKHENbSfw9pQLX0zJT4r/kgsX6mRpPnwZt/3jpLJMMboIPR3hpVQUrs DSlB7J+M5gLGA== From: Kalle Valo To: Qing Wang Cc: Maya Erez , "David S. Miller" , Jakub Kicinski , linux-wireless@vger.kernel.org, wil6210@qti.qualcomm.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: wireless: ath: use div64_u64() instead of do_div() References: <1644395972-4303-1-git-send-email-wangqing@vivo.com> Date: Thu, 10 Feb 2022 14:16:28 +0200 In-Reply-To: <1644395972-4303-1-git-send-email-wangqing@vivo.com> (Qing Wang's message of "Wed, 9 Feb 2022 00:39:32 -0800") Message-ID: <877da2c3xf.fsf@tynnyri.adurom.net> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Qing Wang writes: > From: Wang Qing > > do_div() does a 64-by-32 division. > When the divisor is u64, do_div() truncates it to 32 bits, this means it > can test non-zero and be truncated to zero for division. > > fix do_div.cocci warning: > do_div() does a 64-by-32 division, please consider using div64_u64 instead. > > Signed-off-by: Wang Qing > --- > drivers/net/wireless/ath/wil6210/debugfs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c > index 4c944e5..2cee9dd > --- a/drivers/net/wireless/ath/wil6210/debugfs.c > +++ b/drivers/net/wireless/ath/wil6210/debugfs.c > @@ -1766,7 +1766,7 @@ __acquires(&p->tid_rx_lock) __releases(&p->tid_rx_lock) > seq_puts(s, "\n"); > if (!num_packets) > continue; > - do_div(tx_latency_avg, num_packets); > + div64_u64(tx_latency_avg, num_packets); As you have been pointed out in your other patches, do_div() and div64_u64() work differently. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches