From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> commit c9e143084d1a602f829115612e1ec79df3727c8b upstream. The runtime PM callback may be called as soon as the runtime PM facility is enabled and activated. It means that ->suspend() may be called before we finish probing the device in the ACPI case. Hence, NULL pointer dereference: intel-lpss INT34BA:00: IRQ index 0 not found BUG: kernel NULL pointer dereference, address: 0000000000000030 ... Workqueue: pm pm_runtime_work RIP: 0010:intel_lpss_suspend+0xb/0x40 [intel_lpss] To fix this, first try to register the device and only after that enable runtime PM facility. Fixes: 4b45efe85263 ("mfd: Add support for Intel Sunrisepoint LPSS devices") Reported-by: Orlando Chamberlain <redecorating@xxxxxxxxxxxxxx> Reported-by: Aditya Garg <gargaditya08@xxxxxxxx> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Tested-by: Aditya Garg <gargaditya08@xxxxxxxx> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211101190008.86473-1-andriy.shevchenko@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mfd/intel-lpss-acpi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/mfd/intel-lpss-acpi.c +++ b/drivers/mfd/intel-lpss-acpi.c @@ -102,6 +102,7 @@ static int intel_lpss_acpi_probe(struct { struct intel_lpss_platform_info *info; const struct acpi_device_id *id; + int ret; id = acpi_match_device(intel_lpss_acpi_ids, &pdev->dev); if (!id) @@ -115,10 +116,14 @@ static int intel_lpss_acpi_probe(struct info->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); info->irq = platform_get_irq(pdev, 0); + ret = intel_lpss_probe(&pdev->dev, info); + if (ret) + return ret; + pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); - return intel_lpss_probe(&pdev->dev, info); + return 0; } static int intel_lpss_acpi_remove(struct platform_device *pdev)