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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E26EC4321E for ; Thu, 1 Dec 2022 01:05:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229764AbiLABFE (ORCPT ); Wed, 30 Nov 2022 20:05:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229702AbiLABFC (ORCPT ); Wed, 30 Nov 2022 20:05:02 -0500 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C549C8DFD8; Wed, 30 Nov 2022 17:05:01 -0800 (PST) Received: by mail-ej1-x631.google.com with SMTP id o13so700825ejm.1; Wed, 30 Nov 2022 17:05:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=MozxBZ2nqvbuh4U0WDktsKh5e7hNOw7NR4ywwxy2J/U=; b=eliJBWKgg1OSxa3ReNljvguDDnGkbOu3LnH6dOHFg2mQi7ReErVw1kbpZ/5VRbXi9U nc7SxMFDlwZ1ZjBF2UvgrMNF5pH44SjCfF1Xj4BzybufSUYa+BgRIzSWSSUJE8Ilot9t K9s27L3udHxvMkP17yxMQvhdKAfT8h8HC2wqJvz8TRqmio7dtwAZzSVbvwQyL3lXiNSL lDbaS35t74Us0KTsvTP/9mgGNAYniU4uGyonZVGZvJjirM1BOs41g6GDV9g32nvqzvSh +0lZbiTiQNB70KzuKLLN1hKglVO5oyJnXwJUyeRcVpSCdJvgs7fnbpXodYRLdGzoBGKJ cRKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=MozxBZ2nqvbuh4U0WDktsKh5e7hNOw7NR4ywwxy2J/U=; b=A7QX18XM89FjMw75f6ufuY5oUTpF6qIlTZvazhL+VYQ9NYqrviKPREWB2xcb1bWRnK R/aI34GhZ/2AIGB5blRqekYt4jRK9YUEFi/8nbMMfgZTluO3aKbX7NabW3pvNLydA/XU y1ZSHU2nbd9nMqJSFuiHg2/oF+i58/it9lh7PrPR/z6d9ldyx5YCuuD/UutClmo/Q2Nu OTGIGAw+UpG4XwqVD5mGsDUaKjG19A14ZY4nHDGlKUsQI26rPqO7KONUtW7NiMivQvdw wORRzs3agtIgVWEM35dkGfq7ZbNhw0lZytNEdqe6D9l4/Ili8VwI9szJHf1kVV37+v6W +vkQ== X-Gm-Message-State: ANoB5plfs2QLv4UR5uFdFtFoHbBjxg/IPBoQk5U/AicWIJy4Q0WSZzIS KRElaVYmkldsCjNNiq1kLOcJAELAqoDf9Q== X-Google-Smtp-Source: AA0mqf4k+kxRyNapgUpujfA14SoojjrYy8NxXG87oy+NxZOKEsX9JXLG0aoiGJV/AGoHswdUNUWbEQ== X-Received: by 2002:a17:906:6806:b0:7bf:e1f3:543f with SMTP id k6-20020a170906680600b007bfe1f3543fmr14239894ejr.161.1669856700207; Wed, 30 Nov 2022 17:05:00 -0800 (PST) Received: from skbuf ([188.26.184.222]) by smtp.gmail.com with ESMTPSA id s17-20020a05640217d100b004585eba4baesm1144074edy.80.2022.11.30.17.04.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Nov 2022 17:04:59 -0800 (PST) Date: Thu, 1 Dec 2022 03:04:57 +0200 From: Vladimir Oltean To: Arun Ramadoss Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, woojung.huh@microchip.com, UNGLinuxDriver@microchip.com, andrew@lunn.ch, vivien.didelot@gmail.com, f.fainelli@gmail.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux@armlinux.org.uk, Tristram.Ha@microchip.com, richardcochran@gmail.com, ceggers@arri.de Subject: Re: [Patch net-next v1 04/12] net: dsa: microchip: ptp: Manipulating absolute time using ptp hw clock Message-ID: <20221201010457.ig6jtrp326xj6ux6@skbuf> References: <20221128103227.23171-1-arun.ramadoss@microchip.com> <20221128103227.23171-1-arun.ramadoss@microchip.com> <20221128103227.23171-5-arun.ramadoss@microchip.com> <20221128103227.23171-5-arun.ramadoss@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221128103227.23171-5-arun.ramadoss@microchip.com> <20221128103227.23171-5-arun.ramadoss@microchip.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Nov 28, 2022 at 04:02:19PM +0530, Arun Ramadoss wrote: > diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c > index 184aa57a8489..415522ef4ce9 100644 > --- a/drivers/net/dsa/microchip/ksz_ptp.c > +++ b/drivers/net/dsa/microchip/ksz_ptp.c > @@ -200,6 +209,12 @@ static int ksz_ptp_settime(struct ptp_clock_info *ptp, > goto error_return; > > ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_LOAD_TIME, PTP_LOAD_TIME); > + if (ret) > + goto error_return; > + > + spin_lock_bh(&ptp_data->clock_lock); Why disable bottom halves? Where is the bottom half that this races with? > + ptp_data->clock_time = *ts; > + spin_unlock_bh(&ptp_data->clock_lock); > > error_return: > mutex_unlock(&ptp_data->lock); > @@ -254,6 +269,7 @@ static int ksz_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) > { > struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp); > struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data); > + struct timespec64 delta64 = ns_to_timespec64(delta); > s32 sec, nsec; > u16 data16; > int ret; > @@ -286,15 +302,51 @@ static int ksz_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) > data16 |= PTP_STEP_DIR; > > ret = ksz_write16(dev, REG_PTP_CLK_CTRL, data16); > + if (ret) > + goto error_return; > + > + spin_lock_bh(&ptp_data->clock_lock); > + ptp_data->clock_time = timespec64_add(ptp_data->clock_time, delta64); > + spin_unlock_bh(&ptp_data->clock_lock); > > error_return: > mutex_unlock(&ptp_data->lock); > return ret; > } > > +/* Function is pointer to the do_aux_work in the ptp_clock capability */ > +static long ksz_ptp_do_aux_work(struct ptp_clock_info *ptp) > +{ > + struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp); > + struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data); > + struct timespec64 ts; > + > + mutex_lock(&ptp_data->lock); > + _ksz_ptp_gettime(dev, &ts); > + mutex_unlock(&ptp_data->lock); Why don't you call ksz_ptp_gettime(ptp, &ts) directly? > + > + spin_lock_bh(&ptp_data->clock_lock); > + ptp_data->clock_time = ts; > + spin_unlock_bh(&ptp_data->clock_lock); > + > + return HZ; /* reschedule in 1 second */ > +} > + > static int ksz_ptp_start_clock(struct ksz_device *dev) > { > - return ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ENABLE, PTP_CLK_ENABLE); > + struct ksz_ptp_data *ptp_data = &dev->ptp_data; > + int ret; > + > + ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ENABLE, PTP_CLK_ENABLE); > + if (ret) > + return ret; > + > + spin_lock_bh(&ptp_data->clock_lock); > + ptp_data->clock_time.tv_sec = 0; > + ptp_data->clock_time.tv_nsec = 0; > + spin_unlock_bh(&ptp_data->clock_lock); Does ksz_ptp_start_clock() race with anything? The PTP clock has not even been registered by the time this has been called. This is literally an example of the "spin_lock_init(); spin_lock();" antipattern. > + > + return 0; > }