From patchwork Fri May 5 15:23:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 679393 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52904C77B7F for ; Fri, 5 May 2023 15:25:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232563AbjEEPZY (ORCPT ); Fri, 5 May 2023 11:25:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232033AbjEEPY6 (ORCPT ); Fri, 5 May 2023 11:24:58 -0400 Received: from mail-ed1-x533.google.com (mail-ed1-x533.google.com [IPv6:2a00:1450:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAB361A624 for ; Fri, 5 May 2023 08:23:23 -0700 (PDT) Received: by mail-ed1-x533.google.com with SMTP id 4fb4d7f45d1cf-50bd2d7ba74so28105234a12.1 for ; Fri, 05 May 2023 08:23:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1683300186; x=1685892186; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=PJ0MjyN2tPXJnBiN7+wdwcYqZoiGnIUzbIIwgINFMQk=; b=t9cPpIqjIu7IP/FdOUGPJXKMeX+ktMi3VAhNdww6MEKLAn96lOAvAwzMNvfTc9Jjga WnoJJ131iQm+jk9XN/xGVpPUI64t7dQi0B4H96pUjMS2LeGH0cQSJsGjVBL33BBlXiqM mn41G/W98ig6WwbwBP4ik9n1E0dScC9iDZTbx+UPNxbO0MrjMACBQUIOxjRtsPxDP52v NYCuj+zDxmf79qI+sY4hweoZ3QB8TlacHWry4QETuSMhODClU/hDrmLsx38jxYNCgc+K NEvScEv3zGQ3SXf+QfEANMhP9xpl7hUoAP686nFlLu59btn+5YLdemzDKtqsvKgl4bOf t+Tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683300186; x=1685892186; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=PJ0MjyN2tPXJnBiN7+wdwcYqZoiGnIUzbIIwgINFMQk=; b=jzxhfq83DzzmbyU3O+7EEMuW36pWYWaD2e/nv5QOch3CspFflL40MxDYzcx9zJ8FSq nD1+3beqRiYWAZJ9/GbojCXSIHEt7R+Rbhml4Sa6X6B4S5s9OA4QwFKulSBa1q0LrtHr TLH5vr2WPQgEBcrF0W9r7kgUKEcCymbAcpMyjgo7aY0XQ0vl32B5V49bgdHaZ8hUcVKF MfrDpLjc8O0IOMaYB7ylne/XWDqKDSvpvT9AP7Np3Pl061AScHJt3tNJFwYJm0z7ibcY wf13l05Xk4oIW1hOg++iECZlN82aq7cyZ95xy3DErzc8vvO7DeLyHmoOcuwP/n6/DGxZ hMkw== X-Gm-Message-State: AC+VfDywNYe3ysUMNTZgkX3ntCzxfd1FGDU/6k8tO5jINxMAWwqyDg1C 10PlpkJShIekuo/0Bau9yjFxAw== X-Google-Smtp-Source: ACHHUZ5N5HWekvFr0K66lggYS0aqJcCoHia21AcHCedlBnfdA7aLDt9GxSSzEBIoWYEuVNio2WSufQ== X-Received: by 2002:a17:907:7f02:b0:958:46aa:7f99 with SMTP id qf2-20020a1709077f0200b0095846aa7f99mr2781417ejc.7.1683300186053; Fri, 05 May 2023 08:23:06 -0700 (PDT) Received: from krzk-bin.. ([2a02:810d:15c0:828:52e:24ce:bbc1:127d]) by smtp.gmail.com with ESMTPSA id hy19-20020a1709068a7300b00961277a426dsm1053667ejc.205.2023.05.05.08.23.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 May 2023 08:23:05 -0700 (PDT) From: Krzysztof Kozlowski To: Andy Gross , Bjorn Andersson , Konrad Dybcio , Greg Kroah-Hartman , Jiri Slaby , Akash Asthana , Matthias Kaehlcke , Stephen Boyd , linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Krzysztof Kozlowski , stable@vger.kernel.org Subject: [PATCH] serial: qcom-geni: fix enabling deactivated interrupt Date: Fri, 5 May 2023 17:23:01 +0200 Message-Id: <20230505152301.2181270-1-krzysztof.kozlowski@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org The driver have a race, experienced only with PREEMPT_RT patchset: CPU0 | CPU1 ================================================================== qcom_geni_serial_probe | uart_add_one_port | | serdev_drv_probe | qca_serdev_probe | serdev_device_open | uart_open | uart_startup | qcom_geni_serial_startup | enable_irq | __irq_startup | WARN_ON() | IRQ not activated request_threaded_irq | irq_domain_activate_irq | The warning: 894000.serial: ttyHS1 at MMIO 0x894000 (irq = 144, base_baud = 0) is a MSM serial serial0: tty port ttyHS1 registered WARNING: CPU: 7 PID: 107 at kernel/irq/chip.c:241 __irq_startup+0x78/0xd8 ... qcom_geni_serial 894000.serial: serial engine reports 0 RX bytes in! Adding UART port triggers probe of child serial devices - serdev and eventually Qualcomm Bluetooth hci_qca driver. This opens UART port which enables the interrupt before it got activated in request_threaded_irq(). The issue originates in commit f3974413cf02 ("tty: serial: qcom_geni_serial: Wakeup IRQ cleanup") and discussion on mailing list [1]. However the above commit does not explain why the uart_add_one_port() is moved above requesting interrupt. [1] https://lore.kernel.org/all/5d9f3dfa.1c69fb81.84c4b.30bf@mx.google.com/ Fixes: f3974413cf02 ("tty: serial: qcom_geni_serial: Wakeup IRQ cleanup") Cc: Cc: Stephen Boyd Signed-off-by: Krzysztof Kozlowski --- drivers/tty/serial/qcom_geni_serial.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 08dc3e2a729c..8582479f0211 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1664,19 +1664,18 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) uport->private_data = &port->private_data; platform_set_drvdata(pdev, port); - ret = uart_add_one_port(drv, uport); - if (ret) - return ret; - irq_set_status_flags(uport->irq, IRQ_NOAUTOEN); ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr, IRQF_TRIGGER_HIGH, port->name, uport); if (ret) { dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret); - uart_remove_one_port(drv, uport); return ret; } + ret = uart_add_one_port(drv, uport); + if (ret) + return ret; + /* * Set pm_runtime status as ACTIVE so that wakeup_irq gets * enabled/disabled from dev_pm_arm_wake_irq during system