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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 DE713C76191 for ; Mon, 15 Jul 2019 14:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA39120896 for ; Mon, 15 Jul 2019 14:27:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563200829; bh=6PkvfdoVeYzmKyGDYX7Mc7xSEm+kB0gC4JqS/ob04Sc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FtVHnTdzMOr/g6PpFVIPSm0wcpnhF5QkcTa5Wef6WiCD1WbHx1i6oxrjA6oHBCrwR BVVB3NeMy7YfxbjlYQXJGJyPagr9dFjTsH/4CtntZiuJXNUvQXJ0uh0qiVoUjymQrF MC+u+dC9UkYLqOgmhh04RLRTo6So/u0bXBB5+klQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391441AbfGOO1I (ORCPT ); Mon, 15 Jul 2019 10:27:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:36108 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391433AbfGOO1G (ORCPT ); Mon, 15 Jul 2019 10:27:06 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 38F36206B8; Mon, 15 Jul 2019 14:27:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563200825; bh=6PkvfdoVeYzmKyGDYX7Mc7xSEm+kB0gC4JqS/ob04Sc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mmx8bVR3hFssp3xxQB7h3vxVN0CvlxI+kN03+fE0TXbR2Ny4qokXQFzQVvYBNmrSz MB6qykX1Pxwbx8lQZPoTY8OI/M2tytpHUU+Ju5JtSsHH8bBq71//jQaxxO49GkqrCB enxl8U2GNfd5PY/mRMF0jUyOIMzz2hwilc0gjZDk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Guilherme G. Piccoli" , Przemyslaw Hausman , Sudarsana Reddy Kalluru , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 138/158] bnx2x: Prevent ptp_task to be rescheduled indefinitely Date: Mon, 15 Jul 2019 10:17:49 -0400 Message-Id: <20190715141809.8445-138-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715141809.8445-1-sashal@kernel.org> References: <20190715141809.8445-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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: Sasha Levin --- .../net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 5 ++- .../ethernet/broadcom/bnx2x/bnx2x_ethtool.c | 4 ++- .../net/ethernet/broadcom/bnx2x/bnx2x_main.c | 33 ++++++++++++++----- .../net/ethernet/broadcom/bnx2x/bnx2x_stats.h | 3 ++ 4 files changed, 34 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index 5a727d4729da..e3ce29951c5e 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -3858,9 +3858,12 @@ netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev) 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++; + netdev_err_once(bp->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 */ diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c index c428b0655c26..00f9ed93360c 100644 --- 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) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c index a585f1025a58..2c9af0f420e5 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c @@ -15244,11 +15244,24 @@ static void bnx2x_ptp_task(struct work_struct *work) u32 val_seq; u64 timestamp, ns; struct skb_shared_hwtstamps shhwtstamps; + bool bail = true; + int i; + + /* 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); + } - /* 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) { + 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); @@ -15263,16 +15276,18 @@ static void bnx2x_ptp_task(struct work_struct *work) 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) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h index b2644ed13d06..d55e63692cf3 100644 --- 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 { -- 2.20.1