From patchwork Wed Oct 28 11:46:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Marko X-Patchwork-Id: 11864055 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 139CC921 for ; Wed, 28 Oct 2020 23:21:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB6DF20796 for ; Wed, 28 Oct 2020 23:21:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=sartura-hr.20150623.gappssmtp.com header.i=@sartura-hr.20150623.gappssmtp.com header.b="lVPgk539" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390157AbgJ1XV3 (ORCPT ); Wed, 28 Oct 2020 19:21:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728405AbgJ1XTS (ORCPT ); Wed, 28 Oct 2020 19:19:18 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F093DC0613CF for ; Wed, 28 Oct 2020 16:19:17 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id i1so855251wro.1 for ; Wed, 28 Oct 2020 16:19:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sartura-hr.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=T/mISl4pg2C3Yg5kNFUKUKGfi4SXF1l5cc8dUSNajpE=; b=lVPgk539IYHFg5Ur5L1PfIGULcCeChL7FwHoUoDv1+mm6SG4DS2Xy1L/B/F7fd5+mP f5ADCVWTqB+KUcGrgPIXDxiVUctXLtzHuZJGtBP5hwmDhc8Okj9Cg3KvFn/EqBSoInjW HBvkqW1DpVt/VW6Hw8UQ4zfyvuAx8OcUMB6CjXeBvwIAkM5qMGZez67+8iuB134XJffR APakBda1Pa9buNE9GBl9n8v3BTW0+g4X/Hv0dLM8xCP+lhZ2VYUObPhvXmy/kZgdY027 pyXF3k/yAbW7Dy8sg/6pJ/vWonHbtg6z7Hq1WNj2rRh60pk+h93L2Pe7NTrC2V0LJ983 H2WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=T/mISl4pg2C3Yg5kNFUKUKGfi4SXF1l5cc8dUSNajpE=; b=W4m8iQLSwsFFDy/JH1LxQP5rPWObqlgEzH31y0UcqhQT3nsCU97JIQ8SW39wXJubIF TlO1Ktr8WVic1fusbMxNNMSkoe5MaKmtjrXNCG3iRU7z0LtkojATfN/06/GihykTKPOp ROScVZ2LddDUdSPL21Zhls4dbAS1/+V1nvF4VncCVjTgNOg4o1ntqT+N7XX6Ce9AwemG wPr1ni6Er4WWm/2RHzCt5UZX/g3Z3WQYcBRpdL17YqfT+6m1N/ZigvDvAZpEQdHXxz4s R+tGAicqglC3iAZLKwCxB0p223Kgcx61djtGPsffS3JpQTUwVumd6uIJ1DxkPXKGTeNc ZwFg== X-Gm-Message-State: AOAM530dfBZ0VSKyQcIhS1MZY+bNnQPEKq2PkhR5wmhHn3A+UScPwhlZ JILdoSsHAjZPDMOe0sedwU0fhZO7RxXFpJHF X-Google-Smtp-Source: ABdhPJwaYxESH8zh1v1ocaDitaPtaxX2VCV1QfjTTXry7ovuw85IrQFJV99PZPRQnGLR73/7yfPDnw== X-Received: by 2002:a5d:5387:: with SMTP id d7mr8316847wrv.224.1603885603821; Wed, 28 Oct 2020 04:46:43 -0700 (PDT) Received: from localhost.localdomain (dh207-98-200.xnet.hr. [88.207.98.200]) by smtp.googlemail.com with ESMTPSA id f11sm5873604wml.43.2020.10.28.04.46.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Oct 2020 04:46:43 -0700 (PDT) From: Robert Marko To: agross@kernel.org, bjorn.andersson@linaro.org, wim@linux-watchdog.org, linux@roeck-us.net, linux-arm-msm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Robert Marko , Luka Perkov Subject: [PATCH v2] watchdog: qcom_wdt: set WDOG_HW_RUNNING bit when appropriate Date: Wed, 28 Oct 2020 12:46:35 +0100 Message-Id: <20201028114635.7570-1-robert.marko@sartura.hr> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org If the watchdog hardware is enabled/running during boot, e.g. due to a boot loader configuring it, we must tell the watchdog framework about this fact so that it can ping the watchdog until userspace opens the device and takes over control. Do so using the WDOG_HW_RUNNING flag that exists for exactly that use-case. Given the watchdog driver core doesn't know what timeout was originally set by whoever started the watchdog (boot loader), we make sure to update the timeout in the hardware according to what the watchdog core thinks it is. Signed-off-by: Robert Marko Cc: Luka Perkov --- Changes in v2: * Correct authorship drivers/watchdog/qcom-wdt.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c index ab7465d186fd..28c93a918e38 100644 --- a/drivers/watchdog/qcom-wdt.c +++ b/drivers/watchdog/qcom-wdt.c @@ -152,6 +152,13 @@ static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action, return 0; } +static int qcom_wdt_is_running(struct watchdog_device *wdd) +{ + struct qcom_wdt *wdt = to_qcom_wdt(wdd); + + return (readl(wdt_addr(wdt, WDT_EN)) & 1); +} + static const struct watchdog_ops qcom_wdt_ops = { .start = qcom_wdt_start, .stop = qcom_wdt_stop, @@ -294,6 +301,21 @@ static int qcom_wdt_probe(struct platform_device *pdev) wdt->wdd.timeout = min(wdt->wdd.max_timeout, 30U); watchdog_init_timeout(&wdt->wdd, 0, dev); + if (qcom_wdt_is_running(&wdt->wdd)) { + /* + * Make sure to apply timeout from watchdog core, taking + * the prescaler of this driver here into account (the + * boot loader might be using a different prescaler). + * + * To avoid spurious resets because of different scaling, + * we first disable the watchdog, set the new prescaler + * and timeout, and then re-enable the watchdog. + */ + qcom_wdt_stop(&wdt->wdd); + qcom_wdt_start(&wdt->wdd); + set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); + } + ret = devm_watchdog_register_device(dev, &wdt->wdd); if (ret) return ret;