From 434e5781d8cd2d0ed512d920c6cdeba4b33a2e81 Mon Sep 17 00:00:00 2001
From: Gwendal Grignou <gwendal@chromium.org>
Date: Fri, 29 Mar 2024 07:32:06 -0700
Subject: [PATCH] platform/x86: intel-vbtn: Update tablet mode switch at end of probe
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Git-commit: 434e5781d8cd2d0ed512d920c6cdeba4b33a2e81
Patch-mainline: v6.9-rc4
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/platform/x86/intel-vbtn.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/platform/x86/intel-vbtn.c
+++ b/drivers/platform/x86/intel-vbtn.c
@@ -134,8 +134,6 @@ static int intel_vbtn_input_setup(struct
 	priv->switches_dev->id.bustype = BUS_HOST;
 
 	if (priv->has_switches) {
-		detect_tablet_mode(device);
-
 		ret = input_register_device(priv->switches_dev);
 		if (ret)
 			return ret;
@@ -314,6 +312,9 @@ static int intel_vbtn_probe(struct platf
 		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);
 
 	device_init_wakeup(&device->dev, true);
 	/*