From patchwork Wed Apr 17 20:57:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Judith Mendez X-Patchwork-Id: 790452 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9F15F52F6B; Wed, 17 Apr 2024 20:57:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.23.249 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713387440; cv=none; b=Cgxq0ZJQMC21qAT5sHki0CtyYltuh9xDsx67Vp+M6pucgHaYl0i5FcOlmGoNG1yBIizKMuXxFxyGZBKodnMPyV7EArnrr3ytbgEgrWFGIr5oyq4HpDUsScVbot7p/x0MB2WTAFSe7hwAsp1wLoC+xrYtROetbxvySlPYhlV8BBs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713387440; c=relaxed/simple; bh=BPdpGyW1F/Eojz4Os/i9vRYjSRgNet0NXz4BiUZ19RY=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=nqSl+iGxbH6jAEM9jaSpk8YP+LswIK5W0apGQ4ChJoj72IpW9bS11TnfPbgCq4Bh7U7PyRCgOHMESbVK/ZIyo+aw/dqDMBs3gs46jky0C0SX1nQze/FbsaOAAUVDMKUxzMbayNmlgrR6tBF7BcNvmQMqpepOks17wYjNQpU6VDE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=FDJTSrq2; arc=none smtp.client-ip=198.47.23.249 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="FDJTSrq2" Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 43HKv0uN005769; Wed, 17 Apr 2024 15:57:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1713387420; bh=S95d30u0MX9I2P7CepbqjsFGIsPWOe4MadM11Qo/Kn4=; h=From:To:CC:Subject:Date; b=FDJTSrq2FlVPCa0YMrynwY/rYGqFP9yVdlkOL6S5VCm+In+tjTXnWucWWcEGuNGLK 302z+bQcX6W9ilJ+WdJFVxGYRmggFPlkI8HhLzuwTLxxbLGvykS0CPnBWbL8E0siUT m1ozGP16IiLBdE9fzYiPZsyB08UqHOSB6dokPHlM= Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 43HKv0gJ005616 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 17 Apr 2024 15:57:00 -0500 Received: from DLEE102.ent.ti.com (157.170.170.32) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Wed, 17 Apr 2024 15:57:00 -0500 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Wed, 17 Apr 2024 15:57:00 -0500 Received: from judy-hp.dhcp.ti.com (judy-hp.dhcp.ti.com [128.247.81.105]) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 43HKv0ad071011; Wed, 17 Apr 2024 15:57:00 -0500 From: Judith Mendez To: Wim Van Sebroeck , Guenter Roeck CC: , , Rafael Beims , Vignesh Raghavendra , Nick Saulnier Subject: [PATCH v3] watchdog: rti_wdt: Set min_hw_heartbeat_ms to accommodate a safety margin Date: Wed, 17 Apr 2024 15:57:00 -0500 Message-ID: <20240417205700.3947408-1-jm@ti.com> X-Mailer: git-send-email 2.43.2 Precedence: bulk X-Mailing-List: linux-watchdog@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 On AM62x, the watchdog is pet before the valid window is open. Fix min_hw_heartbeat and accommodate a 2% + static offset safety margin. The static offset accounts for max hardware error. Remove the hack in the driver which shifts the open window boundary, since it is no longer necessary due to the fix mentioned above. cc: stable@vger.kernel.org Fixes: 5527483f8f7c ("watchdog: rti-wdt: attach to running watchdog during probe") Signed-off-by: Judith Mendez --- Changes since v2: - Change safety margin to 2% + max hardware error - remove hack that shifts open window boundary --- drivers/watchdog/rti_wdt.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) base-commit: 860bbe8e618fd62446309e286ab4a83d38201c0a diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 8e1be7ba01039..c7d4de28e1891 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -59,6 +59,8 @@ #define PON_REASON_EOF_NUM 0xCCCCBBBB #define RESERVED_MEM_MIN_SIZE 12 +#define MAX_HW_ERROR 250 + static int heartbeat = DEFAULT_HEARTBEAT; /* @@ -92,7 +94,7 @@ static int rti_wdt_start(struct watchdog_device *wdd) * to be 50% or less than that; we obviouly want to configure the open * window as large as possible so we select the 50% option. */ - wdd->min_hw_heartbeat_ms = 500 * wdd->timeout; + wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR; /* Generate NMI when wdt expires */ writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL); @@ -126,31 +128,33 @@ static int rti_wdt_setup_hw_hb(struct watchdog_device *wdd, u32 wsize) * be petted during the open window; not too early or not too late. * The HW configuration options only allow for the open window size * to be 50% or less than that. + * To avoid any glitches, we accommodate 2% + max hardware error + * safety margin. */ switch (wsize) { case RTIWWDSIZE_50P: - /* 50% open window => 50% min heartbeat */ - wdd->min_hw_heartbeat_ms = 500 * heartbeat; + /* 50% open window => 52% min heartbeat */ + wdd->min_hw_heartbeat_ms = 520 * heartbeat + MAX_HW_ERROR; break; case RTIWWDSIZE_25P: - /* 25% open window => 75% min heartbeat */ - wdd->min_hw_heartbeat_ms = 750 * heartbeat; + /* 25% open window => 77% min heartbeat */ + wdd->min_hw_heartbeat_ms = 770 * heartbeat + MAX_HW_ERROR; break; case RTIWWDSIZE_12P5: - /* 12.5% open window => 87.5% min heartbeat */ - wdd->min_hw_heartbeat_ms = 875 * heartbeat; + /* 12.5% open window => 89.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 895 * heartbeat + MAX_HW_ERROR; break; case RTIWWDSIZE_6P25: - /* 6.5% open window => 93.5% min heartbeat */ - wdd->min_hw_heartbeat_ms = 935 * heartbeat; + /* 6.5% open window => 95.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 955 * heartbeat + MAX_HW_ERROR; break; case RTIWWDSIZE_3P125: - /* 3.125% open window => 96.9% min heartbeat */ - wdd->min_hw_heartbeat_ms = 969 * heartbeat; + /* 3.125% open window => 98.9% min heartbeat */ + wdd->min_hw_heartbeat_ms = 989 * heartbeat + MAX_HW_ERROR; break; default: @@ -228,14 +232,6 @@ static int rti_wdt_probe(struct platform_device *pdev) return -EINVAL; } - /* - * If watchdog is running at 32k clock, it is not accurate. - * Adjust frequency down in this case so that we don't pet - * the watchdog too often. - */ - if (wdt->freq < 32768) - wdt->freq = wdt->freq * 9 / 10; - pm_runtime_enable(dev); ret = pm_runtime_resume_and_get(dev); if (ret < 0) {