platform/x86: acer-wmi: Ignore backlight event

On the Acer Nitro AN515-58, the event 4 - 0 is send by the ACPI
firmware when the backlight up/down keys are pressed. Ignore this
event to avoid spamming the kernel log with error messages, as the
acpi-video driver already handles brightness up/down events.

Reported-by: Bugaddr <Bugaddr@protonmail.com>
Closes: https://bugaddr.tech/posts/2025-11-16-debugging-the-acer-nitro-5-an515-58-fn-f10-keyboard-backlight-bug-on-linux/#wmi-interface-issues
Tested-by: Bugaddr <Bugaddr@protonmail.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20251117155938.3030-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 13eb22b35aa8f86a3c8b839a1258506b99b2da49..d848afc91f87dd2ea6206db586208c073a3c1b64 100644 (file)
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -102,6 +102,7 @@ MODULE_ALIAS("wmi:676AA15E-6A47-4D9F-A2CC-1E6D18D14026");
 
 enum acer_wmi_event_ids {
        WMID_HOTKEY_EVENT = 0x1,
+       WMID_BACKLIGHT_EVENT = 0x4,
        WMID_ACCEL_OR_KBD_DOCK_EVENT = 0x5,
        WMID_GAMING_TURBO_KEY_EVENT = 0x7,
        WMID_AC_EVENT = 0x8,
@@ -2369,6 +2370,9 @@ static void acer_wmi_notify(union acpi_object *obj, void *context)
                        sparse_keymap_report_event(acer_wmi_input_dev, scancode, 1, true);
                }
                break;
+       case WMID_BACKLIGHT_EVENT:
+               /* Already handled by acpi-video */
+               break;
        case WMID_ACCEL_OR_KBD_DOCK_EVENT:
                acer_gsensor_event();
                acer_kbd_dock_event(&return_value);