[PATCH v1 1/3] platform/chrome: chromeos_privacy_screen: Check ACPI_COMPANION()

["Rafael J. Wysocki" <rafael@kernel.org>]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

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
chromeos_privacy_screen driver.

Fixes: d3c2872ae323 ("platform/chrome: Convert ChromeOS privacy-screen driver to platform")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/platform/chrome/chromeos_privacy_screen.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/platform/chrome/chromeos_privacy_screen.c
+++ b/drivers/platform/chrome/chromeos_privacy_screen.c
@@ -104,6 +104,9 @@ static const struct drm_privacy_screen_o
 
 static int chromeos_privacy_screen_probe(struct platform_device *pdev)
 {
+	if (!ACPI_COMPANION(&pdev->dev))
+		return -ENODEV;
+
 	struct drm_privacy_screen *drm_privacy_screen =
 		drm_privacy_screen_register(&pdev->dev,
 					    &chromeos_privacy_screen_ops,