platform/x86: intel-hid: Do not create SW_TABLET_MODE input-dev when a KIOX010A ACPI...

Some 360 degree hinges (yoga) style 2-in-1 devices use 2 accelerometers
to allow the OS to determine the angle between the display and the base
of the device. On Windows these are read by a special HingeAngleService
process which calls an ACPI DSM (Device Specific Method) on the
ACPI KIOX010A device node for the sensor in the display, to let the
firmware know if the 2-in-1 is in tablet- or laptop-mode so that it can
disable the kbd and touchpad to avoid spurious input in tablet-mode.

The linux kxcjk1013 driver calls the DSM for this once at probe time
to ensure that the builtin kbd and touchpad work. On some devices this
causes a "spurious" 0xcd event on the intel-hid ACPI dev. In this case
there is not a functional tablet-mode switch, so we should not register
the tablet-mode switch device.

Cc: Elia Devito <eliadevito@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201207165129.396298-1-hdegoede@redhat.com

diff --git a/drivers/platform/x86/intel-hid.c b/drivers/platform/x86/intel-hid.c
index 66ccdc17a64dca686d622ace5d7c08f36a4525ff..4a396ef54d2e6a2390f6788379d61f0093f7fb0b 100644 (file)
--- a/drivers/platform/x86/intel-hid.c
+++ b/drivers/platform/x86/intel-hid.c
@@ -441,8 +441,23 @@ static void notify_handler(acpi_handle handle, u32 event, void *context)
         * Some convertible have unreliable VGBS return which could cause incorrect
         * SW_TABLET_MODE report, in these cases we enable support when receiving
         * the first event instead of during driver setup.
+        *
+        * Some 360 degree hinges (yoga) style 2-in-1 devices use 2 accelerometers
+        * to allow the OS to determine the angle between the display and the base
+        * of the device. On Windows these are read by a special HingeAngleService
+        * process which calls an ACPI DSM (Device Specific Method) on the
+        * ACPI KIOX010A device node for the sensor in the display, to let the
+        * firmware know if the 2-in-1 is in tablet- or laptop-mode so that it can
+        * disable the kbd and touchpad to avoid spurious input in tablet-mode.
+        *
+        * The linux kxcjk1013 driver calls the DSM for this once at probe time
+        * to ensure that the builtin kbd and touchpad work. On some devices this
+        * causes a "spurious" 0xcd event on the intel-hid ACPI dev. In this case
+        * there is not a functional tablet-mode switch, so we should not register
+        * the tablet-mode switch device.
         */
-       if (!priv->switches && (event == 0xcc || event == 0xcd)) {
+       if (!priv->switches && (event == 0xcc || event == 0xcd) &&
+           !acpi_dev_present("KIOX010A", NULL, -1)) {
                dev_info(&device->dev, "switch event received, enable switches supports\n");
                err = intel_hid_switches_setup(device);
                if (err)