From nobody Sun Sep 14 16:18:09 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7FFCC46467 for ; Thu, 19 Jan 2023 20:41:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230303AbjASUlI (ORCPT ); Thu, 19 Jan 2023 15:41:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230249AbjASUkz (ORCPT ); Thu, 19 Jan 2023 15:40:55 -0500 Received: from inva021.nxp.com (inva021.nxp.com [92.121.34.21]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC34190845; Thu, 19 Jan 2023 12:40:38 -0800 (PST) Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 6A365201829; Thu, 19 Jan 2023 21:40:37 +0100 (CET) Received: from aprdc01srsp001v.ap-rdc01.nxp.com (aprdc01srsp001v.ap-rdc01.nxp.com [165.114.16.16]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 081172017ED; Thu, 19 Jan 2023 21:40:37 +0100 (CET) Received: from lsv03267.swis.in-blr01.nxp.com (lsv03267.swis.in-blr01.nxp.com [92.120.147.107]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id EBCB6180327D; Fri, 20 Jan 2023 04:40:35 +0800 (+08) From: nikhil.gupta@nxp.com To: linux-arm-kernel@lists.infradead.org, Yangbo Lu , vladimir.oltean@nxp.com, richardcochran@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: vakul.garg@nxp.com, rajan.gupta@nxp.com, Nikhil Gupta Subject: [PATCH v2] ptp_qoriq: fix latency in ptp_qoriq_adjtime() operation Date: Fri, 20 Jan 2023 02:10:34 +0530 Message-Id: <20230119204034.7969-1-nikhil.gupta@nxp.com> X-Mailer: git-send-email 2.17.1 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Nikhil Gupta 1588 driver loses about 1us in adjtime operation at PTP slave This is because adjtime operation uses a slow non-atomic tmr_cnt_read() followed by tmr_cnt_write() operation. In the above sequence, since the timer counter operation keeps incrementing, it leads to latency. The tmr_offset register (which is added to TMR_CNT_H/L register giving the current time) must be programmed with the delta nanoseconds. Signed-off-by: Nikhil Gupta Reviewed-by: Vladimir Oltean Tested-by: Vladimir Oltean --- v1->v2: prevent TMR_OFF adjustment in case of eTSEC drivers/ptp/ptp_qoriq.c | 50 ++++++++++++++++++++++++++++++----- include/linux/fsl/ptp_qoriq.h | 1 + 2 files changed, 44 insertions(+), 7 deletions(-) diff --git a/drivers/ptp/ptp_qoriq.c b/drivers/ptp/ptp_qoriq.c index 08f4cf0ad9e3..61530167efe4 100644 --- a/drivers/ptp/ptp_qoriq.c +++ b/drivers/ptp/ptp_qoriq.c @@ -48,6 +48,29 @@ static void tmr_cnt_write(struct ptp_qoriq *ptp_qoriq, u= 64 ns) ptp_qoriq->write(®s->ctrl_regs->tmr_cnt_h, hi); } =20 +static u64 tmr_offset_read(struct ptp_qoriq *ptp_qoriq) +{ + struct ptp_qoriq_registers *regs =3D &ptp_qoriq->regs; + u32 lo, hi; + u64 ns; + + lo =3D ptp_qoriq->read(®s->ctrl_regs->tmroff_l); + hi =3D ptp_qoriq->read(®s->ctrl_regs->tmroff_h); + ns =3D ((u64) hi) << 32; + ns |=3D lo; + return ns; +} + +static void tmr_offset_write(struct ptp_qoriq *ptp_qoriq, u64 delta_ns) +{ + struct ptp_qoriq_registers *regs =3D &ptp_qoriq->regs; + u32 lo =3D delta_ns & 0xffffffff; + u32 hi =3D delta_ns >> 32; + + ptp_qoriq->write(®s->ctrl_regs->tmroff_l, lo); + ptp_qoriq->write(®s->ctrl_regs->tmroff_h, hi); +} + /* Caller must hold ptp_qoriq->lock. */ static void set_alarm(struct ptp_qoriq *ptp_qoriq) { @@ -55,7 +78,9 @@ static void set_alarm(struct ptp_qoriq *ptp_qoriq) u64 ns; u32 lo, hi; =20 - ns =3D tmr_cnt_read(ptp_qoriq) + 1500000000ULL; + ns =3D tmr_cnt_read(ptp_qoriq) + tmr_offset_read(ptp_qoriq) + + 1500000000ULL; + ns =3D div_u64(ns, 1000000000UL) * 1000000000ULL; ns -=3D ptp_qoriq->tclk_period; hi =3D ns >> 32; @@ -207,15 +232,24 @@ EXPORT_SYMBOL_GPL(ptp_qoriq_adjfine); =20 int ptp_qoriq_adjtime(struct ptp_clock_info *ptp, s64 delta) { - s64 now; - unsigned long flags; struct ptp_qoriq *ptp_qoriq =3D container_of(ptp, struct ptp_qoriq, caps); + s64 now, curr_delta; + unsigned long flags; =20 spin_lock_irqsave(&ptp_qoriq->lock, flags); =20 - now =3D tmr_cnt_read(ptp_qoriq); - now +=3D delta; - tmr_cnt_write(ptp_qoriq, now); + /* On LS1021A, eTSEC2 and eTSEC3 do not take into account the TMR_OFF + * adjustment + */ + if (ptp_qoriq->etsec) { + now =3D tmr_cnt_read(ptp_qoriq); + now +=3D delta; + tmr_cnt_write(ptp_qoriq, now); + } else { + curr_delta =3D tmr_offset_read(ptp_qoriq); + curr_delta +=3D delta; + tmr_offset_write(ptp_qoriq, curr_delta); + } set_fipers(ptp_qoriq); =20 spin_unlock_irqrestore(&ptp_qoriq->lock, flags); @@ -232,7 +266,7 @@ int ptp_qoriq_gettime(struct ptp_clock_info *ptp, struc= t timespec64 *ts) =20 spin_lock_irqsave(&ptp_qoriq->lock, flags); =20 - ns =3D tmr_cnt_read(ptp_qoriq); + ns =3D tmr_cnt_read(ptp_qoriq) + tmr_offset_read(ptp_qoriq); =20 spin_unlock_irqrestore(&ptp_qoriq->lock, flags); =20 @@ -253,6 +287,7 @@ int ptp_qoriq_settime(struct ptp_clock_info *ptp, =20 spin_lock_irqsave(&ptp_qoriq->lock, flags); =20 + tmr_offset_write(ptp_qoriq, 0); tmr_cnt_write(ptp_qoriq, ns); set_fipers(ptp_qoriq); =20 @@ -488,6 +523,7 @@ int ptp_qoriq_init(struct ptp_qoriq *ptp_qoriq, void __= iomem *base, =20 /* The eTSEC uses differnt memory map with DPAA/ENETC */ if (of_device_is_compatible(node, "fsl,etsec-ptp")) { + ptp_qoriq->etsec =3D true; ptp_qoriq->regs.ctrl_regs =3D base + ETSEC_CTRL_REGS_OFFSET; ptp_qoriq->regs.alarm_regs =3D base + ETSEC_ALARM_REGS_OFFSET; ptp_qoriq->regs.fiper_regs =3D base + ETSEC_FIPER_REGS_OFFSET; diff --git a/include/linux/fsl/ptp_qoriq.h b/include/linux/fsl/ptp_qoriq.h index 01acebe37fab..b301bf7199d3 100644 --- a/include/linux/fsl/ptp_qoriq.h +++ b/include/linux/fsl/ptp_qoriq.h @@ -149,6 +149,7 @@ struct ptp_qoriq { struct device *dev; bool extts_fifo_support; bool fiper3_support; + bool etsec; int irq; int phc_index; u32 tclk_period; /* nanoseconds */ --=20 2.17.1