From patchwork Tue Jan 16 08:22:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kathiravan Thirumoorthy X-Patchwork-Id: 764228 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (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 8B5D011713; Tue, 16 Jan 2024 08:23:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="TcGROJY1" Received: from pps.filterd (m0279865.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.24/8.17.1.24) with ESMTP id 40G7cIYE014536; Tue, 16 Jan 2024 08:22:54 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= from:date:subject:mime-version:content-type :content-transfer-encoding:message-id:to:cc; s=qcppdkim1; bh=FL4 8iBa/xVcNymrl9/scuXQ7SEn9fK0L2qjW48jo/4c=; b=TcGROJY121C660nL0lR waW4SCxdKMtImdlQhleWRoBabJ+MZT6dLIrbl02K7ri7kTpdGSKwVwl9JNyJnAPs 5zNOyEst+elHW7sPCyI9jNodKhAO+BwM7kB4AMO6WLshF1OeIdhnok5NXBts7VMJ YlYaU2UH9ZA6llTJkm7I/ons4UdJDQNcivHq2lxjySPrlsLqrv3zuYBFi/mJy6HD cRvf6SWMronkzGZ+NNbR+/Xo8WgnYbyIpiNv9d7FhxF0hmmJTxrUNljyBRNhadPV bXxix9YNhUJc2PIzYy/3TmAZVDcgrqkzzOhPUuljE0a2u/FFlAO+HrJbnwV2kWTs nig== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3vn02ctgkc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 16 Jan 2024 08:22:54 +0000 (GMT) Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 40G8MrPI032168 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 16 Jan 2024 08:22:53 GMT Received: from hu-kathirav-blr.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Tue, 16 Jan 2024 00:22:50 -0800 From: Kathiravan Thirumoorthy Date: Tue, 16 Jan 2024 13:52:43 +0530 Subject: [PATCH v2] watchdog: qcom: fine tune the max timeout value calculation Precedence: bulk X-Mailing-List: linux-watchdog@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <20240116-wdt-v2-1-501c7694c3f0@quicinc.com> X-B4-Tracking: v=1; b=H4sIANI8pmUC/1WMMRLCIBBFr5LZWhyWRI1W3sNJIQuYLYQIEXUy3 F1MZ/n+/PcWSDayTXBqFog2c+LgK6hNAzRe/c0KNpVBSdVJRBQvM4udNvJwtOSwM1CfU7SO32v lMlQeOc0hftZoxt/672cUKFRP+67XrUbXnh9PJva0pXCHoZTyBdAndvWYAAAA To: Bjorn Andersson , Konrad Dybcio , Wim Van Sebroeck , Guenter Roeck CC: , , , Kathiravan Thirumoorthy X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1705393370; l=2953; i=quic_kathirav@quicinc.com; s=20230906; h=from:subject:message-id; bh=0E/oeE5cR5fOcIhs2f0ENHP4k2jRmTCCFZ4ckVyUzCo=; b=jJsT3SUMzzIJiY3mc3+LXbHSqbqXrxsEy5VzZ2SUxNzIz1JQGLO9hIpaNFcTJRPTtTyYqiVNH vB1R2eJHZmzB4ztdvZkovFAoa3EoOtiEyawb8+ooaEOY2H0K372Lv9p X-Developer-Key: i=quic_kathirav@quicinc.com; a=ed25519; pk=xWsR7pL6ch+vdZ9MoFGEaP61JUaRf0XaZYWztbQsIiM= X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: RA0-pmIoHGiVuqWsaSev1jzvoI9L16_p X-Proofpoint-GUID: RA0-pmIoHGiVuqWsaSev1jzvoI9L16_p X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-09_01,2023-12-07_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 adultscore=0 spamscore=0 impostorscore=0 phishscore=0 suspectscore=0 priorityscore=1501 bulkscore=0 clxscore=1015 mlxlogscore=999 lowpriorityscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2311290000 definitions=main-2401160066 To determine the max_timeout value, the below calculation is used. max_timeout = 0x10000000 / clk_rate cat /sys/devices/platform/soc@0/b017000.watchdog/watchdog/watchdog0/max_timeout 8388 However, this is not valid for all the platforms. IPQ SoCs starting from IPQ40xx and recent Snapdragron SoCs also has the bark and bite time field length of 20bits, which can hold max up to 32 seconds if the clk_rate is 32KHz. If the user tries to configure the timeout more than 32s, then the value will be truncated and the actual value will not be reflected in the HW. To avoid this, lets add a variable called max_tick_count in the device data, which defines max counter value of the WDT controller. Using this, max-timeout will be calculated in runtime for various WDT contorllers. With this change, we get the proper max_timeout as below and restricts the user from configuring the timeout higher than this. cat /sys/devices/platform/soc@0/b017000.watchdog/watchdog/watchdog0/max_timeout 32 Signed-off-by: Kathiravan Thirumoorthy --- Changes in v2: - drop the minimum timeout change from 30s to 32s - Link to v1: https://lore.kernel.org/r/20240111-wdt-v1-1-28c648b3b1f3@quicinc.com --- drivers/watchdog/qcom-wdt.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- base-commit: 9e21984d62c56a0f6d1fc6f76b646212cfd7fe88 change-id: 20240111-wdt-5bd079ecf14d Best regards, diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c index 9e790f0c2096..006f9c61aa64 100644 --- a/drivers/watchdog/qcom-wdt.c +++ b/drivers/watchdog/qcom-wdt.c @@ -41,6 +41,7 @@ static const u32 reg_offset_data_kpss[] = { struct qcom_wdt_match_data { const u32 *offset; bool pretimeout; + u32 max_tick_count; }; struct qcom_wdt { @@ -177,11 +178,13 @@ static const struct watchdog_info qcom_wdt_pt_info = { static const struct qcom_wdt_match_data match_data_apcs_tmr = { .offset = reg_offset_data_apcs_tmr, .pretimeout = false, + .max_tick_count = 0x10000000U, }; static const struct qcom_wdt_match_data match_data_kpss = { .offset = reg_offset_data_kpss, .pretimeout = true, + .max_tick_count = 0xFFFFFU, }; static int qcom_wdt_probe(struct platform_device *pdev) @@ -236,7 +239,7 @@ static int qcom_wdt_probe(struct platform_device *pdev) */ wdt->rate = clk_get_rate(clk); if (wdt->rate == 0 || - wdt->rate > 0x10000000U) { + wdt->rate > data->max_tick_count) { dev_err(dev, "invalid clock rate\n"); return -EINVAL; } @@ -260,7 +263,7 @@ static int qcom_wdt_probe(struct platform_device *pdev) wdt->wdd.ops = &qcom_wdt_ops; wdt->wdd.min_timeout = 1; - wdt->wdd.max_timeout = 0x10000000U / wdt->rate; + wdt->wdd.max_timeout = data->max_tick_count / wdt->rate; wdt->wdd.parent = dev; wdt->layout = data->offset;