From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (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 0A427226CF6; Thu, 25 Jun 2026 13:02:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782392540; cv=none; b=keo5vkQ92cK/o5+5V8ey1xjDpomMp14g1U0RophIZBDChilZOsuf2Y45Rei5Ac5itZu4ojS1NBlRnde5sbjRqyCI4Wy0i0qZVxqhT8o/Cjbdq4a8i1zTkNi6J8NI8c9iww4CImMsBJDgh4naLMhkUiHF8PyJUoWO2du+j6SLRPQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782392540; c=relaxed/simple; bh=5gVz3GD+JsN14YAXbJsv7T0A96S0m0Kq8gajiDIcAsI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=WEOhwZsl9xTvc2kZ8NE/rCyMFuwplyuOVJpxy1M1jV+it8g+HazwkGmKOy9Sx4wYffCvRHpwYoOnFaOaXQQZPmUbmqtvzdKZgAxVpva+NhxxaycKnK97Ke3OQqOF9SEf1XlOjquzjpdJ5W6TKJcIgohTW5+S2+ceL0rDUlwEVeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=Z+ibaKZ1; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="Z+ibaKZ1" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 8F85B1A0993; Thu, 25 Jun 2026 13:02:17 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 643275FF03; Thu, 25 Jun 2026 13:02:17 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 99232104C9531; Thu, 25 Jun 2026 15:02:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1782392533; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding; bh=0BqDniKI2eMO7o9mzNR7O6RD+KCeOBbHHaik/jgiuZE=; b=Z+ibaKZ1DO8mSkOm2ZsS+jE6pLtyRc7zfB3/jkGamU4bBi+I9LMIYuSgZlKVbcTU4rVonp /VhCDY4rA1j/4tNn0Cw8wswmLCIAGz/kReUCXbTWzHizfwh86tT1aExdiXDRnrpc3h583A wxyIiURUlypGFzDKxal2HsU75U3SaOhNO3Lcv5O2tTkYZLU+f7nRavGJWeUHkyKti7Kdd/ I00Cph3sJndfrxrIadqIVDzx6Tov6NO8ok89P/FVJhuDhUXdkhJeJ+cU9UP8t+O+iHPL11 0XP0RL/WyMPvKjBQXUk+5pGQ3D+OWsURRJBQzEQmlA8Op+WBNpe/M70OfFLdCA== From: alexandre.belloni@bootlin.com To: Alexandre Belloni Cc: =?UTF-8?q?Gr=C3=A9gory=20Clement?= , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] rtc: mv: fix potential race condition Date: Thu, 25 Jun 2026 15:02:00 +0200 Message-ID: <20260625130202.1621692-1-alexandre.belloni@bootlin.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 From: Alexandre Belloni Since the driver allocates the IRQ using devm_request_irq(), this means the IRQ is going to be automatically unregistered by devres after mv_rtc_remove() returns. However, mv_rtc_remove() explicitly disables the hardware clock before devres teardown happens so the interrupt handler may run while the clock is disabled leading to a possible bus hang when accessing registers. Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-mv.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/drivers/rtc/rtc-mv.c b/drivers/rtc/rtc-mv.c index f88976fd6d5d..c0f1bcd838e3 100644 --- a/drivers/rtc/rtc-mv.c +++ b/drivers/rtc/rtc-mv.c @@ -219,17 +219,15 @@ static int __init mv_rtc_probe(struct platform_device *pdev) if (IS_ERR(pdata->ioaddr)) return PTR_ERR(pdata->ioaddr); - pdata->clk = devm_clk_get(&pdev->dev, NULL); - /* Not all SoCs require a clock.*/ - if (!IS_ERR(pdata->clk)) - clk_prepare_enable(pdata->clk); + pdata->clk = devm_clk_get_optional_prepared(&pdev->dev, NULL); + if (IS_ERR(pdata->clk)) + return PTR_ERR(pdata->clk); /* make sure the 24 hour mode is enabled */ rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); if (rtc_time & RTC_HOURS_12H_MODE) { dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n"); - ret = -EINVAL; - goto out; + return -EINVAL; } /* make sure it is actually functional */ @@ -238,8 +236,7 @@ static int __init mv_rtc_probe(struct platform_device *pdev) rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); if (rtc_time == 0x01000000) { dev_err(&pdev->dev, "internal RTC not ticking\n"); - ret = -ENODEV; - goto out; + return -ENODEV; } } @@ -249,8 +246,7 @@ static int __init mv_rtc_probe(struct platform_device *pdev) pdata->rtc = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(pdata->rtc)) { - ret = PTR_ERR(pdata->rtc); - goto out; + return PTR_ERR(pdata->rtc); } if (pdata->irq >= 0) { @@ -275,9 +271,6 @@ static int __init mv_rtc_probe(struct platform_device *pdev) ret = devm_rtc_register_device(pdata->rtc); if (!ret) return 0; -out: - if (!IS_ERR(pdata->clk)) - clk_disable_unprepare(pdata->clk); return ret; } @@ -288,9 +281,6 @@ static void __exit mv_rtc_remove(struct platform_device *pdev) if (pdata->irq >= 0) device_init_wakeup(&pdev->dev, false); - - if (!IS_ERR(pdata->clk)) - clk_disable_unprepare(pdata->clk); } #ifdef CONFIG_OF -- 2.54.0