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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E1668C76186 for ; Wed, 24 Jul 2019 19:32:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2173229F3 for ; Wed, 24 Jul 2019 19:32:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563996742; bh=b+VJZUq5RJQd3coOrPQ9j4fNfb9ALoRVXO3ikaJbDjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tYLR7mPSyqb576jPujNRyOlp/iLdFICXwhOHRXzbT2d5BYggOywwp6qlp/CNyewyb PWA290i1OHCnRExLOysFWM6o2jvkZPpuAxK/ny1P82g41ReANLjBsoGzLKqoyzuYo7 Qe9SlgB2gevQFBk56cmcRbe++KO5pIgFn1QZgfxM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388242AbfGXTcV (ORCPT ); Wed, 24 Jul 2019 15:32:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:53588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388622AbfGXTcR (ORCPT ); Wed, 24 Jul 2019 15:32:17 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7CCBF229F3; Wed, 24 Jul 2019 19:32:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563996737; bh=b+VJZUq5RJQd3coOrPQ9j4fNfb9ALoRVXO3ikaJbDjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wQw0CV5sLP398ZwtVbAH6K7akWwEjeyPrljHWHZi+njLpHgrrFs62fkADJp2326Jo 6hWY69iEHD0s/VYCU+cGYDMaXJ5m4kH0GnfdIXXxWkSq88o+/0gW8ACZDbMI0DVvIW SeqEnTz+p0Ad6VEXcKdKS+y2UUsp03soocNX18u8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vedang Patel , Aaron Brown , "David S. Miller" , Sasha Levin Subject: [PATCH 5.2 198/413] igb: clear out skb->tstamp after reading the txtime Date: Wed, 24 Jul 2019 21:18:09 +0200 Message-Id: <20190724191748.748535878@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191735.096702571@linuxfoundation.org> References: <20190724191735.096702571@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 1e08511d5d01884a3c9070afd52a47799312074a ] If a packet which is utilizing the launchtime feature (via SO_TXTIME socket option) also requests the hardware transmit timestamp, the hardware timestamp is not delivered to the userspace. This is because the value in skb->tstamp is mistaken as the software timestamp. Applications, like ptp4l, request a hardware timestamp by setting the SOF_TIMESTAMPING_TX_HARDWARE socket option. Whenever a new timestamp is detected by the driver (this work is done in igb_ptp_tx_work() which calls igb_ptp_tx_hwtstamps() in igb_ptp.c[1]), it will queue the timestamp in the ERR_QUEUE for the userspace to read. When the userspace is ready, it will issue a recvmsg() call to collect this timestamp. The problem is in this recvmsg() call. If the skb->tstamp is not cleared out, it will be interpreted as a software timestamp and the hardware tx timestamp will not be successfully sent to the userspace. Look at skb_is_swtx_tstamp() and the callee function __sock_recv_timestamp() in net/socket.c for more details. Signed-off-by: Vedang Patel Tested-by: Aaron Brown Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/igb/igb_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 39f33afc479c..005c1693efc8 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -5687,6 +5687,7 @@ static void igb_tx_ctxtdesc(struct igb_ring *tx_ring, */ if (tx_ring->launchtime_enable) { ts = ns_to_timespec64(first->skb->tstamp); + first->skb->tstamp = 0; context_desc->seqnum_seed = cpu_to_le32(ts.tv_nsec / 32); } else { context_desc->seqnum_seed = 0; -- 2.20.1