platform/x86: intel-vbtn: Update tablet mode switch at end of probe

[ Upstream commit 434e5781d8cd2d0ed512d920c6cdeba4b33a2e81 ]

ACER Vivobook Flip (TP401NAS) virtual intel switch is implemented as
follow:

   Device (VGBI)
   {
       Name (_HID, EisaId ("INT33D6") ...
       Name (VBDS, Zero)
       Method (_STA, 0, Serialized)  // _STA: Status ...
       Method (VBDL, 0, Serialized)
       {
           PB1E |= 0x20
           VBDS |= 0x40
       }
       Method (VGBS, 0, Serialized)
       {
           Return (VBDS) /* \_SB_.PCI0.SBRG.EC0_.VGBI.VBDS */
       }
       ...
    }

By default VBDS is set to 0. At boot it is set to clamshell (bit 6 set)
only after method VBDL is executed.

Since VBDL is now evaluated in the probe routine later, after the device
is registered, the retrieved value of VBDS was still 0 ("tablet mode")
when setting up the virtual switch.

Make sure to evaluate VGBS after VBDL, to ensure the
convertible boots in clamshell mode, the expected default.

Fixes: 26173179fae1 ("platform/x86: intel-vbtn: Eval VBDL after registering our notifier")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240329143206.2977734-3-gwendal@chromium.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/platform/x86/intel/vbtn.c b/drivers/platform/x86/intel/vbtn.c
index 6fb3e597c57aa8c625ad66b86e2549b66a89c294..4e9d3f25c35d08fac39672332f0591ae5cb4c859 100644 (file)
--- a/drivers/platform/x86/intel/vbtn.c
+++ b/drivers/platform/x86/intel/vbtn.c
@@ -136,8 +136,6 @@ static int intel_vbtn_input_setup(struct platform_device *device)
        priv->switches_dev->id.bustype = BUS_HOST;
 
        if (priv->has_switches) {
-               detect_tablet_mode(&device->dev);
-
                ret = input_register_device(priv->switches_dev);
                if (ret)
                        return ret;
@@ -316,6 +314,9 @@ static int intel_vbtn_probe(struct platform_device *device)
                if (ACPI_FAILURE(status))
                        dev_err(&device->dev, "Error VBDL failed with ACPI status %d\n", status);
        }
+       // Check switches after buttons since VBDL may have side effects.
+       if (has_switches)
+               detect_tablet_mode(&device->dev);
 
        device_init_wakeup(&device->dev, true);
        /*