[RFC PATCH 3/3] platform/x86: ideapad-laptop: do not bind the WMI event devices without the VPC

[David Cemin <dcemin@nvidia.com>]

ideapad-laptop binds the Fn key and Esc WMI event GUIDs unconditionally,
but ideapad_wmi_notify() only acts when the VPC platform driver has
probed and set ideapad_shared. On machines that expose the WMI GUIDs
without the IdeaPad VPC device (VPC2004) the driver claims the WMI
device and then drops every event.

Decline the WMI devices when there is no VPC2004, so the device stays
free for a consumer that can report the events, such as the Lenovo WMI
hotkeys driver.

Signed-off-by: David Cemin <dcemin@nvidia.com>
---
 drivers/platform/x86/lenovo/ideapad-laptop.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/platform/x86/lenovo/ideapad-laptop.c b/drivers/platform/x86/lenovo/ideapad-laptop.c
index 91a8d11c79c5..44ae248c5a4d 100644
--- a/drivers/platform/x86/lenovo/ideapad-laptop.c
+++ b/drivers/platform/x86/lenovo/ideapad-laptop.c
@@ -2278,6 +2278,14 @@ static int ideapad_wmi_probe(struct wmi_device *wdev, const void *context)
 {
 	struct ideapad_wmi_private *wpriv;
 
+	/*
+	 * The events are only delivered once the VPC platform driver is bound
+	 * (ideapad_shared).  Without the VPC device this driver can never
+	 * report them, so leave the WMI device to another consumer.
+	 */
+	if (!acpi_dev_found("VPC2004"))
+		return -ENODEV;
+
 	wpriv = devm_kzalloc_obj(&wdev->dev, *wpriv);
 	if (!wpriv)
 		return -ENOMEM;
-- 
2.56.1