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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 24F1DC76186 for ; Mon, 29 Jul 2019 19:33:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E128621655 for ; Mon, 29 Jul 2019 19:33:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428788; bh=g44n4eyLeqegZrQ8j2ByDwsIPXCmoHLnxnLPMeE1QzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kbCgty6DWyiLfq8dw1Z0VLUfHKliN/2jfYzLNKPK9kSENlmKR+rZz1qbPI4C+y0f0 0UzHUaoHeuY2IhjX62NUT2e4YMXPQE8x+OEF1/5rfON6DiFtTEWBvbAgHRF62tAhe2 ShIzk9sSaVDvf+bOveuzewpHWoJetKweYv/Cgj98= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729496AbfG2TdG (ORCPT ); Mon, 29 Jul 2019 15:33:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:46878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730294AbfG2TdC (ORCPT ); Mon, 29 Jul 2019 15:33:02 -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 B401621655; Mon, 29 Jul 2019 19:33:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428781; bh=g44n4eyLeqegZrQ8j2ByDwsIPXCmoHLnxnLPMeE1QzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zUsmDpo8jjBzHtGSwIqPPwGrrDULuuyqHCB/mfaZHWAfRIUjS/XmqSZITGM3tjHhY Qwj1JAskdUdEhj0KEttyphAflYgn/MEp7CDEZHwbH7U8nU/nyLEbBygN0CkG1V5kbq xZXwiam68H8OgS18D8/gJ1w3xouWZWv/Oq+PUN1U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sudarsana Reddy Kalluru , "Guilherme G. Piccoli" , "David S. Miller" , Przemyslaw Hausman Subject: [PATCH 4.14 182/293] bnx2x: Prevent ptp_task to be rescheduled indefinitely Date: Mon, 29 Jul 2019 21:21:13 +0200 Message-Id: <20190729190838.448707483@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190820.321094988@linuxfoundation.org> References: <20190729190820.321094988@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 From: "Guilherme G. Piccoli" [ Upstream commit 3c91f25c2f72ba6001775a5932857c1d2131c531 ] Currently bnx2x ptp worker tries to read a register with timestamp information in case of TX packet timestamping and in case it fails, the routine reschedules itself indefinitely. This was reported as a kworker always at 100% of CPU usage, which was narrowed down to be bnx2x ptp_task. By following the ioctl handler, we could narrow down the problem to an NTP tool (chrony) requesting HW timestamping from bnx2x NIC with RX filter zeroed; this isn't reproducible for example with ptp4l (from linuxptp) since this tool requests a supported RX filter. It seems NIC FW timestamp mechanism cannot work well with RX_FILTER_NONE - driver's PTP filter init routine skips a register write to the adapter if there's not a supported filter request. This patch addresses the problem of bnx2x ptp thread's everlasting reschedule by retrying the register read 10 times; between the read attempts the thread sleeps for an increasing amount of time starting in 1ms to give FW some time to perform the timestamping. If it still fails after all retries, we bail out in order to prevent an unbound resource consumption from bnx2x. The patch also adds an ethtool statistic for accounting the skipped TX timestamp packets and it reduces the priority of timestamping error messages to prevent log flooding. The code was tested using both linuxptp and chrony. Reported-and-tested-by: Przemyslaw Hausman Suggested-by: Sudarsana Reddy Kalluru Signed-off-by: Guilherme G. Piccoli Acked-by: Sudarsana Reddy Kalluru Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 5 ++- drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c | 4 +- drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 33 ++++++++++++++------ drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h | 3 + 4 files changed, 34 insertions(+), 11 deletions(-) --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -3859,9 +3859,12 @@ netdev_tx_t bnx2x_start_xmit(struct sk_b if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) { if (!(bp->flags & TX_TIMESTAMPING_EN)) { + bp->eth_stats.ptp_skip_tx_ts++; BNX2X_ERR("Tx timestamping was not enabled, this packet will not be timestamped\n"); } else if (bp->ptp_tx_skb) { - BNX2X_ERR("The device supports only a single outstanding packet to timestamp, this packet will not be timestamped\n"); + bp->eth_stats.ptp_skip_tx_ts++; + dev_err_once(&bp->dev->dev, + "Device supports only a single outstanding packet to timestamp, this packet won't be timestamped\n"); } else { skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; /* schedule check for Tx timestamp */ --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c @@ -182,7 +182,9 @@ static const struct { { STATS_OFFSET32(driver_filtered_tx_pkt), 4, false, "driver_filtered_tx_pkt" }, { STATS_OFFSET32(eee_tx_lpi), - 4, true, "Tx LPI entry count"} + 4, true, "Tx LPI entry count"}, + { STATS_OFFSET32(ptp_skip_tx_ts), + 4, false, "ptp_skipped_tx_tstamp" }, }; #define BNX2X_NUM_STATS ARRAY_SIZE(bnx2x_stats_arr) --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c @@ -15264,11 +15264,24 @@ static void bnx2x_ptp_task(struct work_s u32 val_seq; u64 timestamp, ns; struct skb_shared_hwtstamps shhwtstamps; + bool bail = true; + int i; - /* Read Tx timestamp registers */ - val_seq = REG_RD(bp, port ? NIG_REG_P1_TLLH_PTP_BUF_SEQID : - NIG_REG_P0_TLLH_PTP_BUF_SEQID); - if (val_seq & 0x10000) { + /* FW may take a while to complete timestamping; try a bit and if it's + * still not complete, may indicate an error state - bail out then. + */ + for (i = 0; i < 10; i++) { + /* Read Tx timestamp registers */ + val_seq = REG_RD(bp, port ? NIG_REG_P1_TLLH_PTP_BUF_SEQID : + NIG_REG_P0_TLLH_PTP_BUF_SEQID); + if (val_seq & 0x10000) { + bail = false; + break; + } + msleep(1 << i); + } + + if (!bail) { /* There is a valid timestamp value */ timestamp = REG_RD(bp, port ? NIG_REG_P1_TLLH_PTP_BUF_TS_MSB : NIG_REG_P0_TLLH_PTP_BUF_TS_MSB); @@ -15283,16 +15296,18 @@ static void bnx2x_ptp_task(struct work_s memset(&shhwtstamps, 0, sizeof(shhwtstamps)); shhwtstamps.hwtstamp = ns_to_ktime(ns); skb_tstamp_tx(bp->ptp_tx_skb, &shhwtstamps); - dev_kfree_skb_any(bp->ptp_tx_skb); - bp->ptp_tx_skb = NULL; DP(BNX2X_MSG_PTP, "Tx timestamp, timestamp cycles = %llu, ns = %llu\n", timestamp, ns); } else { - DP(BNX2X_MSG_PTP, "There is no valid Tx timestamp yet\n"); - /* Reschedule to keep checking for a valid timestamp value */ - schedule_work(&bp->ptp_task); + DP(BNX2X_MSG_PTP, + "Tx timestamp is not recorded (register read=%u)\n", + val_seq); + bp->eth_stats.ptp_skip_tx_ts++; } + + dev_kfree_skb_any(bp->ptp_tx_skb); + bp->ptp_tx_skb = NULL; } void bnx2x_set_rx_ts(struct bnx2x *bp, struct sk_buff *skb) --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h @@ -207,6 +207,9 @@ struct bnx2x_eth_stats { u32 driver_filtered_tx_pkt; /* src: Clear-on-Read register; Will not survive PMF Migration */ u32 eee_tx_lpi; + + /* PTP */ + u32 ptp_skip_tx_ts; }; struct bnx2x_eth_q_stats {