From patchwork Mon Feb 24 17:06:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabrice Gasnier X-Patchwork-Id: 13988560 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0B490C021A4 for ; Mon, 24 Feb 2025 17:21:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=GTr3MiF+X8E++5/d1k9zNiwhyWX8NQucbTgDgyPXgzM=; b=1+nd6ev50oYBv9pSszbKvqkAkD msa7L8RHTNTXjIdGb6qNASuasLo9swLHgf6+5t8E/JnXEVp3kMc/Fk2Pi8+wxNuI+OpGr5yAD/zjH EL6xfW+8s4vfxSEcEruMDmKZG/l7SRcVK3IhMWty9lGlj4Q0VYhfOM/wxv4XG9YWbNh0vD1tZaazX 4OAq7mpUM370wGLZS0kfyRy0zOSyMvDGIidLnd7sRsEqlV/IykMRWoKj6dfr9a49M1vSUfRsizJGM dvxrHzZBSHtzKGDvlpFjBxIOR/er7MYpT26SMCejNTtmMlPWsZpFbMjXy3xcZONjgUdDv9xAARDd2 iJXtLqbw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tmc8e-0000000EbMO-1Ml7; Mon, 24 Feb 2025 17:21:04 +0000 Received: from mx07-00178001.pphosted.com ([185.132.182.106]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tmc74-0000000Eb2G-40BK for linux-arm-kernel@lists.infradead.org; Mon, 24 Feb 2025 17:19:28 +0000 Received: from pps.filterd (m0241204.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 51OCixFa013141; Mon, 24 Feb 2025 18:18:53 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= cc:content-transfer-encoding:content-type:date:from:message-id :mime-version:subject:to; s=selector1; bh=GTr3MiF+X8E++5/d1k9zNi whyWX8NQucbTgDgyPXgzM=; b=FUDrhTvWnYasctYRtyGBXE9jaB4Bb2fd9efqkz U0icqpJMn4T+2PKvta5rvS3Ovu1JM0cXFy/eTYjh9gqTWmAyR6fyvovwYnJgbFWM bg2RG0PdeEvQs4Cn/iABWV+uMzcoJLfYZ6ovLb9eJcVs8nKsW0ksVFFeYn0Qz1x6 pHGP5gRfJLlC4sVthXChcXruHPGgvIT5xI/q4+xDG8jTA5vYzPYDTJf2si1s2Yug GoQuKbknH2VNCz5CJwmkqQPyAJzlR2KFA34H0LMECIX9l5XGM8KE/dHZO4NiJF9a GGtSSqKkrJazdZsg9JOgyjN8h7BhRHZtORuRJIxQ985ml4Tg== Received: from beta.dmz-ap.st.com (beta.dmz-ap.st.com [138.198.100.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 44y6t20jjm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 24 Feb 2025 18:18:53 +0100 (CET) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id 3B60640044; Mon, 24 Feb 2025 18:17:49 +0100 (CET) Received: from Webmail-eu.st.com (eqndag1node4.st.com [10.75.129.133]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id BC8145387F7; Mon, 24 Feb 2025 18:07:40 +0100 (CET) Received: from SAFDAG1NODE1.st.com (10.75.90.17) by EQNDAG1NODE4.st.com (10.75.129.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 24 Feb 2025 18:07:40 +0100 Received: from localhost (10.252.23.75) by SAFDAG1NODE1.st.com (10.75.90.17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 24 Feb 2025 18:07:40 +0100 From: Fabrice Gasnier To: CC: , , , , , , Subject: [PATCH] counter: stm32-lptimer-cnt: fix error handling when enabling Date: Mon, 24 Feb 2025 18:06:57 +0100 Message-ID: <20250224170657.3368236-1-fabrice.gasnier@foss.st.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.252.23.75] X-ClientProxiedBy: SHFCAS1NODE2.st.com (10.75.129.73) To SAFDAG1NODE1.st.com (10.75.90.17) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-02-24_08,2025-02-24_02,2024-11-22_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250224_091927_542417_1D18E83A X-CRM114-Status: GOOD ( 14.64 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In case the stm32_lptim_set_enable_state() fails to update CMP and ARR, a timeout error is raised, by regmap_read_poll_timeout. It may happen, when the lptimer runs on a slow clock, and the clock is gated only few times during the polling. Badly, when this happen, STM32_LPTIM_ENABLE in CR register has been set. So the 'enable' state in sysfs wrongly lies on the counter being correctly enabled, due to CR is read as one in stm32_lptim_is_enabled(). To fix both issues: - enable the clock before writing CMP, ARR and polling ISR bits. It will avoid the possible timeout error. - clear the ENABLE bit in CR and disable the clock in the error path. Fixes: d8958824cf07 ("iio: counter: Add support for STM32 LPTimer") Signed-off-by: Fabrice Gasnier --- drivers/counter/stm32-lptimer-cnt.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c index cf73f65baf60..b249c8647639 100644 --- a/drivers/counter/stm32-lptimer-cnt.c +++ b/drivers/counter/stm32-lptimer-cnt.c @@ -58,37 +58,43 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv, return 0; } + ret = clk_enable(priv->clk); + if (ret) + goto disable_cnt; + /* LP timer must be enabled before writing CMP & ARR */ ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->ceiling); if (ret) - return ret; + goto disable_clk; ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0); if (ret) - return ret; + goto disable_clk; /* ensure CMP & ARR registers are properly written */ ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val, (val & STM32_LPTIM_CMPOK_ARROK) == STM32_LPTIM_CMPOK_ARROK, 100, 1000); if (ret) - return ret; + goto disable_clk; ret = regmap_write(priv->regmap, STM32_LPTIM_ICR, STM32_LPTIM_CMPOKCF_ARROKCF); if (ret) - return ret; + goto disable_clk; - ret = clk_enable(priv->clk); - if (ret) { - regmap_write(priv->regmap, STM32_LPTIM_CR, 0); - return ret; - } priv->enabled = true; /* Start LP timer in continuous mode */ return regmap_update_bits(priv->regmap, STM32_LPTIM_CR, STM32_LPTIM_CNTSTRT, STM32_LPTIM_CNTSTRT); + +disable_clk: + clk_disable(priv->clk); +disable_cnt: + regmap_write(priv->regmap, STM32_LPTIM_CR, 0); + + return ret; } static int stm32_lptim_setup(struct stm32_lptim_cnt *priv, int enable)