From patchwork Mon Mar 15 13:52:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 401513 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 3A4A8C2BB55 for ; Mon, 15 Mar 2021 13:59:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C73164F45 for ; Mon, 15 Mar 2021 13:59:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232415AbhCON6y (ORCPT ); Mon, 15 Mar 2021 09:58:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:37476 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231992AbhCON6M (ORCPT ); Mon, 15 Mar 2021 09:58:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0292464F16; Mon, 15 Mar 2021 13:58:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816692; bh=/790nOz32xaX0xWdPUA7Nda3o6/xLtAllPmcVfB2N34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=skP56bEcomf33+cigT9DtJr7EROqxwqI+gxx5SjM3DtFYfE9zNaERfGZYWLL8QfNC iHXbPsqSoxmG9hQRewZfwvb6Rwxv7iB7yK0rLHpk3gEHmVl4W+lKgTxYOZq90SIe2S cVN/8j7G569swi3rXEHZGQFSEdOEPqP8ipR7ndjM= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xie He , Martin Schiller , "David S. Miller" Subject: [PATCH 5.11 067/306] net: lapbether: Remove netif_start_queue / netif_stop_queue Date: Mon, 15 Mar 2021 14:52:10 +0100 Message-Id: <20210315135509.913984853@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135507.611436477@linuxfoundation.org> References: <20210315135507.611436477@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman From: Xie He commit f7d9d4854519fdf4d45c70a4d953438cd88e7e58 upstream. For the devices in this driver, the default qdisc is "noqueue", because their "tx_queue_len" is 0. In function "__dev_queue_xmit" in "net/core/dev.c", devices with the "noqueue" qdisc are specially handled. Packets are transmitted without being queued after a "dev->flags & IFF_UP" check. However, it's possible that even if this check succeeds, "ops->ndo_stop" may still have already been called. This is because in "__dev_close_many", "ops->ndo_stop" is called before clearing the "IFF_UP" flag. If we call "netif_stop_queue" in "ops->ndo_stop", then it's possible in "__dev_queue_xmit", it sees the "IFF_UP" flag is present, and then it checks "netif_xmit_stopped" and finds that the queue is already stopped. In this case, it will complain that: "Virtual device ... asks to queue packet!" To prevent "__dev_queue_xmit" from generating this complaint, we should not call "netif_stop_queue" in "ops->ndo_stop". We also don't need to call "netif_start_queue" in "ops->ndo_open", because after a netdev is allocated and registered, the "__QUEUE_STATE_DRV_XOFF" flag is initially not set, so there is no need to call "netif_start_queue" to clear it. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xie He Acked-by: Martin Schiller Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/wan/lapbether.c | 3 --- 1 file changed, 3 deletions(-) --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -292,7 +292,6 @@ static int lapbeth_open(struct net_devic return -ENODEV; } - netif_start_queue(dev); return 0; } @@ -300,8 +299,6 @@ static int lapbeth_close(struct net_devi { int err; - netif_stop_queue(dev); - if ((err = lapb_unregister(dev)) != LAPB_OK) pr_err("lapb_unregister error: %d\n", err);