From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751586AbcGPGUv (ORCPT ); Sat, 16 Jul 2016 02:20:51 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:60176 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751331AbcGPGUt (ORCPT ); Sat, 16 Jul 2016 02:20:49 -0400 Date: Fri, 15 Jul 2016 23:20:48 -0700 (PDT) Message-Id: <20160715.232048.1780795244111833927.davem@davemloft.net> To: f.fainelli@gmail.com Cc: netdev@vger.kernel.org, michael.chan@broadcom.com, huangjw@broadcom.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] bnxt_en: Fix potential race condition in bnxt_tx_enable() From: David Miller In-Reply-To: <1468626125-31732-1-git-send-email-f.fainelli@gmail.com> References: <1468626125-31732-1-git-send-email-f.fainelli@gmail.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 15 Jul 2016 23:20:49 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Florian Fainelli Date: Fri, 15 Jul 2016 16:42:01 -0700 > @@ -4599,7 +4599,9 @@ static void bnxt_tx_enable(struct bnxt *bp) > for (i = 0; i < bp->tx_nr_rings; i++) { > txr = &bp->tx_ring[i]; > txq = netdev_get_tx_queue(bp->dev, i); > + __netif_tx_lock(txq, smp_processor_id()); > txr->dev_state = 0; > + __netif_tx_unlock(txq); You're going to have to explain how this could possibly cause a problem, because I'm pretty sure it can't. Either the reader sees 0, or non-zero, in this value. And adding locking around this assignment does not change that at all.