platform/x86: dell/dell-rbtn: Check ACPI_COMPANION() against NULL

Every platform driver can be forced to match a device that doesn't match
its list of device IDs because of device_match_driver_override(), so
platform drivers that rely on the existence of a device's ACPI companion
object need to verify its presence.

Accordingly, add a requisite ACPI_COMPANION() check against NULL to the
platform/x86 dell-rbtn driver.

Fixes: 19ebacfb442b ("platform/x86: dell/dell-rbtn: Convert ACPI driver to a platform one")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/2276487.irdbgypaU6@rafael.j.wysocki
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/dell/dell-rbtn.c b/drivers/platform/x86/dell/dell-rbtn.c
index 34af9f4ff7419ca7795fafb588bf818db2ea09a9..180b8c6720e653cecbff8e948e335320e23056be 100644 (file)
--- a/drivers/platform/x86/dell/dell-rbtn.c
+++ b/drivers/platform/x86/dell/dell-rbtn.c
@@ -396,11 +396,15 @@ static void rbtn_cleanup(struct device *dev)
 
 static int rbtn_probe(struct platform_device *pdev)
 {
-       struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
        struct rbtn_data *rbtn_data;
+       struct acpi_device *device;
        enum rbtn_type type;
        int ret = 0;
 
+       device = ACPI_COMPANION(&pdev->dev);
+       if (!device)
+               return -ENODEV;
+
        type = rbtn_check(device);
        if (type == RBTN_UNKNOWN) {
                dev_info(&pdev->dev, "Unknown device type\n");