This is a note to let you know that I've just added the patch titled serial: qcom-geni: fix enabling deactivated interrupt to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-qcom-geni-fix-enabling-deactivated-interrupt.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5f949f140f73696f64acb89a1f16ff9153d017e0 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Date: Fri, 5 May 2023 17:23:01 +0200 Subject: serial: qcom-geni: fix enabling deactivated interrupt From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> commit 5f949f140f73696f64acb89a1f16ff9153d017e0 upstream. 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@xxxxxxxxxxxxx/ Fixes: f3974413cf02 ("tty: serial: qcom_geni_serial: Wakeup IRQ cleanup") Cc: <stable@xxxxxxxxxxxxxxx> Cc: Stephen Boyd <swboyd@xxxxxxxxxxxx> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230505152301.2181270-1-krzysztof.kozlowski@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/qcom_geni_serial.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1483,19 +1483,18 @@ static int qcom_geni_serial_probe(struct platform_set_drvdata(pdev, port); port->handle_rx = console ? handle_rx_console : handle_rx_uart; - 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 Patches currently in stable-queue which might be from krzysztof.kozlowski@xxxxxxxxxx are queue-6.1/serial-qcom-geni-fix-enabling-deactivated-interrupt.patch queue-6.1/arm64-dts-qcom-sdm845-polaris-drop-inexistent-proper.patch queue-6.1/soundwire-qcom-gracefully-handle-too-many-ports-in-d.patch