platform/x86: ideapad-laptop: Stop sending KEY_TOUCHPAD_TOGGLE

Commit 5829f8a8 ("platform/x86: ideapad-laptop: Send
KEY_TOUCHPAD_TOGGLE on some models") made ideapad-laptop send
KEY_TOUCHPAD_TOGGLE when we receive an ACPI notify with VPC event bit 5 set
and the touchpad-state has not been changed by the EC itself already.

This was done under the assumption that this would be good to do to make
the touchpad-toggle hotkey work on newer models where the EC does not
toggle the touchpad on/off itself (because it is not routed through
the PS/2 controller, but uses I2C).

But it turns out that at least some models, e.g. the Yoga 7-15ITL5 the EC
triggers an ACPI notify with VPC event bit 5 set on resume, which would
now cause a spurious KEY_TOUCHPAD_TOGGLE on resume to which the desktop
environment responds by disabling the touchpad in software, breaking
the touchpad (until manually re-enabled) on resume.

It was never confirmed that sending KEY_TOUCHPAD_TOGGLE actually improves
things on new models and at least some new models like the Yoga 7-15ITL5
don't have a touchpad on/off toggle hotkey at all, while still sending
ACPI notify events with VPC event bit 5 set.

So it seems best to revert the change to send KEY_TOUCHPAD_TOGGLE when
receiving an ACPI notify events with VPC event bit 5 and the touchpad
state as reported by the EC has not changed.

Note this is not a full revert the code to cache the last EC touchpad
state is kept to avoid sending spurious KEY_TOUCHPAD_ON / _OFF events
on resume.

Fixes: 5829f8a8 ("platform/x86: ideapad-laptop: Send KEY_TOUCHPAD_TOGGLE on some models")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217234
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230330194644.64628-1-hdegoede@redhat.com

drivers/platform/x86/ideapad-laptop.c

@@ -1170,7 +1170,6 @@ static const struct key_entry ideapad_keymap[] = {
 	{ KE_KEY,  65, { KEY_PROG4 } },
 	{ KE_KEY,  66, { KEY_TOUCHPAD_OFF } },
 	{ KE_KEY,  67, { KEY_TOUCHPAD_ON } },
-	{ KE_KEY,  68, { KEY_TOUCHPAD_TOGGLE } },
 	{ KE_KEY, 128, { KEY_ESC } },
 
 	/*
@@ -1526,18 +1525,16 @@ static void ideapad_sync_touchpad_state(struct ideapad_private *priv, bool send_
 	if (priv->features.ctrl_ps2_aux_port)
 		i8042_command(&param, value ? I8042_CMD_AUX_ENABLE : I8042_CMD_AUX_DISABLE);
 
-	if (send_events) {
-		/*
-		 * On older models the EC controls the touchpad and toggles it
-		 * on/off itself, in this case we report KEY_TOUCHPAD_ON/_OFF.
-		 * If the EC did not toggle, report KEY_TOUCHPAD_TOGGLE.
-		 */
-		if (value != priv->r_touchpad_val) {
-			ideapad_input_report(priv, value ? 67 : 66);
-			sysfs_notify(&priv->platform_device->dev.kobj, NULL, "touchpad");
-		} else {
-			ideapad_input_report(priv, 68);
-		}
+	/*
+	 * On older models the EC controls the touchpad and toggles it on/off
+	 * itself, in this case we report KEY_TOUCHPAD_ON/_OFF. Some models do
+	 * an acpi-notify with VPC bit 5 set on resume, so this function get
+	 * called with send_events=true on every resume. Therefor if the EC did
+	 * not toggle, do nothing to avoid sending spurious KEY_TOUCHPAD_TOGGLE.
+	 */
+	if (send_events && value != priv->r_touchpad_val) {
+		ideapad_input_report(priv, value ? 67 : 66);
+		sysfs_notify(&priv->platform_device->dev.kobj, NULL, "touchpad");
 	}
 
 	priv->r_touchpad_val = value;