From 495cd7f858b45d2ffa9b685bba3a8c23c1ca4dd3 Mon Sep 17 00:00:00 2001 From: Lovekesh Solanki Date: Sun, 20 Sep 2026 17:05:41 +0530 Subject: Input: i8042 - add nomux quirk for Fujitsu LIFEBOOK U7410 On the Fujitsu LIFEBOOK U7410 the internal keyboard and touchpad die shortly after boot if i8042 multiplexing controller is probed and switched to muxed mode. These multiplexing setup commands disturb the EC emulated keyboard and atkbd reports "Spurious ACK" and "Unknown key pressed" warnings, after which both keyboard and touchpad stop delivering events. Both touchpad and keyboard work in BIOS and GRUB. Disabling multiplexer using i8042.nomux=1 makes both devices work on warm/cold boot. Add a DMI quirk to force nomux mode for this model. Reported-by: Heiko Brey Link: https://lore.kernel.org/all/89f36f3f5e4c2d07b9ff72bc0b355875c336e498.camel@gmx.de/ Signed-off-by: Lovekesh Solanki Link: https://patch.msgid.link/20260920113541.1484808-1-lovekeshsolanki00@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov --- drivers/input/serio/i8042-acpipnpio.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/input/serio/i8042-acpipnpio.h b/drivers/input/serio/i8042-acpipnpio.h index 54eb36870..1b1c5d4ac 100644 --- a/drivers/input/serio/i8042-acpipnpio.h +++ b/drivers/input/serio/i8042-acpipnpio.h @@ -671,6 +671,15 @@ static const struct dmi_system_id i8042_dmi_quirk_table[] __initconst = { }, .driver_data = (void *)(SERIO_QUIRK_NOAUX) }, + { + /* Fujitsu LIFEBOOK U7410 */ + /* Mux mode also disturbs the EC keyboard, causing spurious ACKs */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU CLIENT COMPUTING LIMITED"), + DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK U7410"), + }, + .driver_data = (void *)(SERIO_QUIRK_NOMUX) + }, { /* Gigabyte M912 */ .matches = { -- cgit v1.3.1