[PATCH 5.16 25/37] mfd: intel-lpss: Fix too early PM enablement in the ACPI ->probe()

From: Greg Kroah-Hartman
Date: Fri Jan 14 2022 - 03:26:11 EST


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
@@ -136,6 +136,7 @@ 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)
@@ -149,10 +150,14 @@ 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)