platform/x86: thinkpad_acpi: Do not send ACPI netlink events for unknown hotkeys

Do not send ACPI netlink events for unknown hotkeys, to avoid userspace
starting to rely on them. Instead these should be added to the keymap to
send evdev events.

This should not cause a behavior change for existing laptop models since
all currently known 0x1xxx events have a mapping.

In hindsight the ACPI netlink events should have been suppressed for
the adaptive keyboard and extended hotkeys events too. But the kernel has
been sending ACPI netlink events for those for a long time now, so we
cannot just stop sending them without potentially causing issues for
existing users who may depend on these.
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240424122834.19801-16-hdegoede@redhat.com

drivers/platform/x86/thinkpad_acpi.c

@@ -2250,7 +2250,7 @@ static void tpacpi_input_send_tabletsw(void)
 	}
 }
 
-static bool tpacpi_input_send_key(const u32 hkey)
+static bool tpacpi_input_send_key(const u32 hkey, bool *send_acpi_ev)
 {
 	unsigned int keycode, scancode;
 
@@ -2271,6 +2271,14 @@ static bool tpacpi_input_send_key(const u32 hkey)
 		scancode = hkey - TP_HKEY_EV_EXTENDED_KEY_START +
 			   TP_ACPI_HOTKEYSCAN_EXTENDED_START;
 	} else {
+		/*
+		 * Do not send ACPI netlink events for unknown hotkeys, to
+		 * avoid userspace starting to rely on them. Instead these
+		 * should be added to the keymap to send evdev events.
+		 */
+		if (send_acpi_ev)
+			*send_acpi_ev = false;
+
 		return false;
 	}
 
@@ -2298,7 +2306,7 @@ static struct tp_acpi_drv_struct ibm_hotkey_acpidriver;
 /* Do NOT call without validating scancode first */
 static void tpacpi_hotkey_send_key(unsigned int scancode)
 {
-	tpacpi_input_send_key(TP_HKEY_EV_ORIG_KEY_START + scancode);
+	tpacpi_input_send_key(TP_HKEY_EV_ORIG_KEY_START + scancode, NULL);
 }
 
 static void hotkey_read_nvram(struct tp_nvram_state *n, const u32 m)
@@ -3734,7 +3742,7 @@ static bool hotkey_notify_hotkey(const u32 hkey, bool *send_acpi_ev)
 			return true;
 	}
 
-	return tpacpi_input_send_key(hkey);
+	return tpacpi_input_send_key(hkey, send_acpi_ev);
 }
 
 /* 0x2000-0x2FFF: Wakeup reason */