i8042: Fujitsu LIFEBOOK U7410 needs i8042.nomux (keyboard and touchpad dead)

i8042: Fujitsu LIFEBOOK U7410 needs i8042.nomux (keyboard and touchpad dead)

[Heiko Brey]

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Hi,

On a Fujitsu LIFEBOOK U7410 the internal keyboard and touchpad are dead
after boot with the default i8042 settings. Both work in BIOS and GRUB.
The kernel registers the devices (AT Translated Set 2 keyboard, and the
Elan touchpad 04F3:3092 via I2C-HID), but evtest shows no events on
either.

System:
  Kernel:          7.0.0-31-generic (Linux Mint 22.3)
  sys_vendor:      FUJITSU CLIENT COMPUTING LIMITED
  product_name:    LIFEBOOK U7410
  board_name:      FJNB2D4
  BIOS:            Version 2.12, 06/23/2020

With default parameters, dmesg reports:

  i8042: Detected active multiplexing controller, rev 1.1
  atkbd serio0: Spurious ACK on isa0060/serio0 (repeated)
  atkbd serio0: Unknown key pressed (translated set 2, code 0x0)

What I tried:
  - i8042.nopnp i8042.reset: no change
  - i8042.nomux=1 i8042.reset: keyboard and touchpad work, on warm and
    cold boot. The multiplexing message and the Spurious ACK messages
    no longer appear.
  (I have not tested i8042.nomux=1 without i8042.reset.)

Could a DMI quirk with nomux be added for this model?

Thanks,

Heiko
-- 
Heiko Brey

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Re: i8042: Fujitsu LIFEBOOK U7410 needs i8042.nomux (keyboard and touchpad dead)

[Lovekesh Solanki]

Hi thanks for the report,

On Sat, Sep 19, 2026 at 11:52:19AM +0200, Heiko Brey wrote:
> What I tried:
>   - i8042.nopnp i8042.reset: no change
>   - i8042.nomux=1 i8042.reset: keyboard and touchpad work, on warm and
>     cold boot. The multiplexing message and the Spurious ACK messages
>     no longer appear.
>   (I have not tested i8042.nomux=1 without i8042.reset.)
> 
> Could a DMI quirk with nomux be added for this model?
Yes, but could you first see whether including the reset parameter is
needed? Or it works just with nomux=1 so we won't include unneeded
quirks in the patch.

Thanks,
Lovekesh

Re: i8042: Fujitsu LIFEBOOK U7410 needs i8042.nomux (keyboard and touchpad dead)

[Heiko Brey]

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Am Samstag, dem 19.09.2026 um 23:59 +0530 schrieb Lovekesh Solanki:
> Hi thanks for the report,
> 
> On Sat, Sep 19, 2026 at 11:52:19AM +0200, Heiko Brey wrote:
> > What I tried:
> >    - i8042.nopnp i8042.reset: no change
> >    - i8042.nomux=1 i8042.reset: keyboard and touchpad work, on warm
> > and
> >      cold boot. The multiplexing message and the Spurious ACK
> > messages
> >      no longer appear.
> >    (I have not tested i8042.nomux=1 without i8042.reset.)
> > 
> > Could a DMI quirk with nomux be added for this model?
> Yes, but could you first see whether including the reset parameter is
> needed? Or it works just with nomux=1 so we won't include unneeded
> quirks in the patch.
> 
> Thanks,
> Lovekesh

Hi Lovekesh,

thanks for the quick reply.

I tested with only i8042.nomux=1 (without i8042.reset). Keyboard and
touchpad work on both a warm reboot and a cold boot, so the reset
parameter is not needed.

/proc/cmdline during the test:
  BOOT_IMAGE=/boot/vmlinuz-7.0.0-31-generic ... ro quiet splash
i8042.nomux=1

Happy to test a patch on this machine once you have one.

Best regards,
Heiko

-- 
Heiko Brey

GPG-Fingerprint: C8A4 ABA2 B404 407D 83F1 46FC 0A66 455F CA5A 1277
Info zu verschlüsselten Emails: https://emailselfdefense.fsf.org/de/

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Re: i8042: Fujitsu LIFEBOOK U7410 needs i8042.nomux (keyboard and touchpad dead)

[Lovekesh Solanki]

On Sun, Sep 20, 2026 at 10:03:39AM +0200, Heiko Brey wrote:
> Hi Lovekesh,
> 
> thanks for the quick reply.
> 
> I tested with only i8042.nomux=1 (without i8042.reset). Keyboard and
> touchpad work on both a warm reboot and a cold boot, so the reset
> parameter is not needed.
> 
> /proc/cmdline during the test:
>   BOOT_IMAGE=/boot/vmlinuz-7.0.0-31-generic ... ro quiet splash
> i8042.nomux=1
> 
> Happy to test a patch on this machine once you have one.
Great! I'll just submit the patch upstream directly within the hour.
You could test it and reply with a Tested-by tag on it.

Regards,
Lovekesh