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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 11A0CC433E0 for ; Sun, 5 Jul 2020 15:07:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB30B2075D for ; Sun, 5 Jul 2020 15:07:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="i946XFFC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727051AbgGEPHf (ORCPT ); Sun, 5 Jul 2020 11:07:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726826AbgGEPHf (ORCPT ); Sun, 5 Jul 2020 11:07:35 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FB09C061794; Sun, 5 Jul 2020 08:07:35 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id t15so1522186pjq.5; Sun, 05 Jul 2020 08:07:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:to:cc:references:from:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=oWGjpobOxzlgwjb1kbGd6v3TL3FL54/58+CeQAJAuJ0=; b=i946XFFCKKCU8GwBwPNdoOw3vsFKf9p/fhx8beEFAlkdb9uNPcthLKLOKUTlrdSLz3 kjS7d8qyKyHaRjy6YiaJDxXxSNdNMdAMGfwMBrAW14PzAdh+RL91tVl+Q59Rw/NXiTxS 20YhY5EaRtTnLrN5A8WNHM8/aCtwBcO0KYT6SXURYnS7+pCIhqbG00DBllv/B0aZeGsm 900zWbGXvF9wyKOrXbaN/HtWKRncm3hpN5KaQDWt/9xQKHu9k3ZiXsad1V2jamvNxDNi dade+mPdftbso0wToPi6lPWHaSv+Sj1C4GDpHgxQx3Nq/Z1g+j8DC+00aQ+xR91T3EIE TJ8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=oWGjpobOxzlgwjb1kbGd6v3TL3FL54/58+CeQAJAuJ0=; b=GQsjLdK5LeNVc32YunpG0n6EaZm7ZZhbY9eHkV5w+juSI6g1tvyfF38ufEZAWeATNl HMVoVPBk8Tgd+mftY4l8vETmZzkRPRETnjQEnp3sS7U/SCsTsh7TOy0DcXYWZGh7wF/q pyicG3vhCfFDlWRWrIUn9NBhLB58y+7fl3Xg9zmpMcpLBFMPeqd5iDdxqrUoqYoDyUnc VBh1skK5WhrrEWoBBrgoYI2EVn54pIk3krKYllx+w5Eg6KZfVroWm8rCk4Brn5tvGh8+ OKYjNAJir6hOjoicA0xulqWvSyykddiPp4nxHesz0iNJIzdFOoPRdZ//qw2q+OpyrIYx 9cKQ== X-Gm-Message-State: AOAM530Pq+Iq9sNxLtlOrlifovu0Zc55YClKop911571iCrTe0tT3Uuv XCKYDhDlHuO4kub35Pw54TPJ0MtOOlo= X-Google-Smtp-Source: ABdhPJzc31fO0WKOCE7yIYY7Ka6DQ0woxsrO7Cyb4HcmjxkwR4wOwSWRqdLdqey1KdMOfSRpIQrQSA== X-Received: by 2002:a17:90b:3555:: with SMTP id lt21mr50581897pjb.234.1593961654790; Sun, 05 Jul 2020 08:07:34 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id r204sm9951785pfc.134.2020.07.05.08.07.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 05 Jul 2020 08:07:34 -0700 (PDT) Subject: Re: [PATCHv2 4/5] watchdog: rti-wdt: attach to running watchdog during probe To: Tero Kristo , wim@linux-watchdog.org, linux-watchdog@vger.kernel.org Cc: linux-kernel@vger.kernel.org, jan.kiszka@siemens.com References: <20200703120406.7092-1-t-kristo@ti.com> <20200703120406.7092-5-t-kristo@ti.com> From: Guenter Roeck Autocrypt: addr=linux@roeck-us.net; keydata= xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAlVcphcFCRmg06EACgkQyx8mb86fmYFg0RAA nzXJzuPkLJaOmSIzPAqqnutACchT/meCOgMEpS5oLf6xn5ySZkl23OxuhpMZTVX+49c9pvBx hpvl5bCWFu5qC1jC2eWRYU+aZZE4sxMaAGeWenQJsiG9lP8wkfCJP3ockNu0ZXXAXwIbY1O1 c+l11zQkZw89zNgWgKobKzrDMBFOYtAh0pAInZ9TSn7oA4Ctejouo5wUugmk8MrDtUVXmEA9 7f9fgKYSwl/H7dfKKsS1bDOpyJlqhEAH94BHJdK/b1tzwJCFAXFhMlmlbYEk8kWjcxQgDWMu GAthQzSuAyhqyZwFcOlMCNbAcTSQawSo3B9yM9mHJne5RrAbVz4TWLnEaX8gA5xK3uCNCeyI sqYuzA4OzcMwnnTASvzsGZoYHTFP3DQwf2nzxD6yBGCfwNGIYfS0i8YN8XcBgEcDFMWpOQhT Pu3HeztMnF3HXrc0t7e5rDW9zCh3k2PA6D2NV4fews9KDFhLlTfCVzf0PS1dRVVWM+4jVl6l HRIAgWp+2/f8dx5vPc4Ycp4IsZN0l1h9uT7qm1KTwz+sSl1zOqKD/BpfGNZfLRRxrXthvvY8 BltcuZ4+PGFTcRkMytUbMDFMF9Cjd2W9dXD35PEtvj8wnEyzIos8bbgtLrGTv/SYhmPpahJA l8hPhYvmAvpOmusUUyB30StsHIU2LLccUPPOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAlVcpi8FCRmg08MACgkQyx8mb86fmYHNRQ/+ J0OZsBYP4leJvQF8lx9zif+v4ZY/6C9tTcUv/KNAE5leyrD4IKbnV4PnbrVhjq861it/zRQW cFpWQszZyWRwNPWUUz7ejmm9lAwPbr8xWT4qMSA43VKQ7ZCeTQJ4TC8kjqtcbw41SjkjrcTG wF52zFO4bOWyovVAPncvV9eGA/vtnd3xEZXQiSt91kBSqK28yjxAqK/c3G6i7IX2rg6pzgqh hiH3/1qM2M/LSuqAv0Rwrt/k+pZXE+B4Ud42hwmMr0TfhNxG+X7YKvjKC+SjPjqp0CaztQ0H nsDLSLElVROxCd9m8CAUuHplgmR3seYCOrT4jriMFBtKNPtj2EE4DNV4s7k0Zy+6iRQ8G8ng QjsSqYJx8iAR8JRB7Gm2rQOMv8lSRdjva++GT0VLXtHULdlzg8VjDnFZ3lfz5PWEOeIMk7Rj trjv82EZtrhLuLjHRCaG50OOm0hwPSk1J64R8O3HjSLdertmw7eyAYOo4RuWJguYMg5DRnBk WkRwrSuCn7UG+qVWZeKEsFKFOkynOs3pVbcbq1pxbhk3TRWCGRU5JolI4ohy/7JV1TVbjiDI HP/aVnm6NC8of26P40Pg8EdAhajZnHHjA7FrJXsy3cyIGqvg9os4rNkUWmrCfLLsZDHD8FnU mDW4+i+XlNFUPUYMrIKi9joBhu18ssf5i5Q= Message-ID: <8eecaa6a-2e0e-14b3-473a-0674f9b2be26@roeck-us.net> Date: Sun, 5 Jul 2020 08:07:33 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200703120406.7092-5-t-kristo@ti.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org On 7/3/20 5:04 AM, Tero Kristo wrote: > If the RTI watchdog is running already during probe, the driver must > configure itself to match the HW. Window size and timeout is probed from > hardware, and the last keepalive ping is adjusted to match it also. > > Signed-off-by: Tero Kristo > --- > drivers/watchdog/rti_wdt.c | 26 +++++++++++++++++++++++--- > 1 file changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c > index 110bfc8d0bb3..987e5a798cb4 100644 > --- a/drivers/watchdog/rti_wdt.c > +++ b/drivers/watchdog/rti_wdt.c > @@ -213,6 +213,7 @@ static int rti_wdt_probe(struct platform_device *pdev) > struct watchdog_device *wdd; > struct rti_wdt_device *wdt; > struct clk *clk; > + u32 last_ping = 0; > > wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); > if (!wdt) > @@ -258,11 +259,8 @@ static int rti_wdt_probe(struct platform_device *pdev) > wdd->min_timeout = 1; > wdd->max_hw_heartbeat_ms = (WDT_PRELOAD_MAX << WDT_PRELOAD_SHIFT) / > wdt->freq * 1000; > - wdd->timeout = DEFAULT_HEARTBEAT; What if the watchdog is not running ? > wdd->parent = dev; > > - watchdog_init_timeout(wdd, heartbeat, dev); > - > watchdog_set_drvdata(wdd, wdt); > watchdog_set_nowayout(wdd, 1); > watchdog_set_restart_priority(wdd, 128); > @@ -274,12 +272,34 @@ static int rti_wdt_probe(struct platform_device *pdev) > goto err_iomap; > } > > + if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) { > + u32 time_left; > + > + set_bit(WDOG_HW_RUNNING, &wdd->status); > + time_left = rti_wdt_get_timeleft(wdd); > + heartbeat = readl(wdt->base + RTIDWDPRLD); > + heartbeat <<= WDT_PRELOAD_SHIFT; > + heartbeat /= wdt->freq; > + This ignores any heartbeat configured as module parameter, which most people will consider unexpected. It might be worthwhile documenting that. > + wsize = readl(wdt->base + RTIWWDSIZECTRL); > + ret = rti_wdt_setup_hw_hb(wdd); > + if (ret) > + goto err_iomap; > + > + last_ping = -(time_left - heartbeat) * 1000; Why the double negation ? last_ping = (heartbeat - time_left) * 1000; seems simpler. Also, what if heartbeat - time_left is negative for whatever reason ? I am not sure if it is a good idea to call rti_wdt_get_timeleft() here. It might be better to add a helper function such as rti_wdt_get_timeleft_ms() to return the time left in milli-seconds for improved accuracy. > + } > + > + watchdog_init_timeout(wdd, heartbeat, dev); > + > ret = watchdog_register_device(wdd); > if (ret) { > dev_err(dev, "cannot register watchdog device\n"); > goto err_iomap; > } > > + if (last_ping) > + watchdog_set_last_hw_keepalive(wdd, last_ping); > + > return 0; > > err_iomap: >