platform/chrome: chromeos_privacy_screen: Check ACPI_COMPANION()

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>
Link: https://lore.kernel.org/r/3357444.5fSG56mABF@rafael.j.wysocki
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

diff --git a/drivers/platform/chrome/chromeos_privacy_screen.c b/drivers/platform/chrome/chromeos_privacy_screen.c
index abc5d189a38944067ad3d5437260f64dcb4e12b9..407b04207de2fdbb27550ae36c2e2f543b536e72 100644 (file)
--- 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_ops chromeos_privacy_screen_ops = {
 
 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,