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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 274D0C3526B for ; Mon, 15 Nov 2021 18:11:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C68A6331D for ; Mon, 15 Nov 2021 18:11:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240906AbhKOSOM (ORCPT ); Mon, 15 Nov 2021 13:14:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:50940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237992AbhKOR2d (ORCPT ); Mon, 15 Nov 2021 12:28:33 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A05786326A; Mon, 15 Nov 2021 17:19:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636996748; bh=LbtfJxVw5J2ou5RSUK4eQ9EBcue+ThouKW02Wug48dI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HN8WSXn3g8IPKkymo+jyk0IoFLORIJ1usz/VdDQTj2Uu0dKrhYkjJV6PTAzVDKGbw C2Meuf07DGhxyvU53yf9NMSBNq9CxEJTP27Jdn22IbCU3hRyEwGbyBTVP9EmH0y+e5 8l/AJcI3KC1KHTV3T2Mo7tmLYTTODWGG5i47DqBo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Abdul Haleem , Vaishnavi Bhat , Sukadev Bhattiprolu , Dany Madden , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 254/355] ibmvnic: dont stop queue in xmit Date: Mon, 15 Nov 2021 18:02:58 +0100 Message-Id: <20211115165321.960800692@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165313.549179499@linuxfoundation.org> References: <20211115165313.549179499@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sukadev Bhattiprolu [ Upstream commit 8878e46fcfd46b19964bd90e13b25dd94cbfc9be ] If adapter's resetting bit is on, discard the packet but don't stop the transmit queue - instead leave that to the reset code. With this change, it is possible that we may get several calls to ibmvnic_xmit() that simply discard packets and return. But if we stop the queue here, we might end up doing so just after __ibmvnic_open() started the queues (during a hard/soft reset) and before the ->resetting bit was cleared. If that happens, there will be no one to restart queue and transmissions will be blocked indefinitely. This can cause a TIMEOUT reset and with auto priority failover enabled, an unnecessary FAILOVER reset to less favored backing device and then a FAILOVER back to the most favored backing device. If we hit the window repeatedly, we can get stuck in a loop of TIMEOUT, FAILOVER, FAILOVER resets leaving the adapter unusable for extended periods of time. Fixes: 7f5b030830fe ("ibmvnic: Free skb's in cases of failure in transmit") Reported-by: Abdul Haleem Reported-by: Vaishnavi Bhat Signed-off-by: Sukadev Bhattiprolu Reviewed-by: Dany Madden Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/ibm/ibmvnic.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index cfe7229593ead..059eaa13e2c6d 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -1462,8 +1462,6 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) netdev_tx_t ret = NETDEV_TX_OK; if (test_bit(0, &adapter->resetting)) { - if (!netif_subqueue_stopped(netdev, skb)) - netif_stop_subqueue(netdev, queue_num); dev_kfree_skb_any(skb); tx_send_failed++; -- 2.33.0