[PATCH 2/2] platform/x86: intel-vbtn: Detect switch position before registering the input-device

From: Hans de Goede
Date: Sun May 10 2020 - 08:21:14 EST


Setting the initial state of input-device switches must be done before
registering the input-device.

Otherwise the initial state will get send out as an event as soon
as input_sync() gets called.

E.g. when undocking a tablet using intel-vbtn to report SW_TABLET_MODE
and SW_DOCK before this commit we would get (evemu-record output):

E: 0.000001 0005 0005 0001 # EV_SW / SW_DOCK 1
E: 0.000001 0000 0000 0000 # ------------ SYN_REPORT (0) ---------- +0ms
E: 0.000109 0005 0005 0000 # EV_SW / SW_DOCK 0
E: 0.000109 0000 0000 0000 # ------------ SYN_REPORT (0) ---------- +0ms
E: 0.000133 0005 0001 0001 # EV_SW / SW_TABLET_MODE 1
E: 0.000133 0000 0000 0000 # ------------ SYN_REPORT (0) ---------- +0ms

The first SW_DOCK=1 report is spurious, setting the initial switch
state before registering the input-device fixes this.

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/platform/x86/intel-vbtn.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/intel-vbtn.c b/drivers/platform/x86/intel-vbtn.c
index 29984154f8e4..ef92c1c3adbd 100644
--- a/drivers/platform/x86/intel-vbtn.c
+++ b/drivers/platform/x86/intel-vbtn.c
@@ -111,6 +111,9 @@ static int intel_vbtn_input_setup(struct platform_device *device)
priv->input_dev->name = "Intel Virtual Button driver";
priv->input_dev->id.bustype = BUS_HOST;

+ if (priv->has_switches)
+ detect_tablet_mode(device);
+
return input_register_device(priv->input_dev);
}

@@ -217,9 +220,6 @@ static int intel_vbtn_probe(struct platform_device *device)
return err;
}

- if (priv->has_switches)
- detect_tablet_mode(device);
-
status = acpi_install_notify_handler(handle,
ACPI_DEVICE_NOTIFY,
notify_handler,
--
2.26.0