Re: [PATCH] i2c: acpi: Add ELAN0662 to i2c_acpi_force_100khz_device_ids

[Yuqi Xu]

Hi Andi,

I just wanted to gently ping on this patch. It has been a little over
two weeks, and Mika acked it on Sep 18.

Please let me know if there is anything else you would like changed.
Otherwise, I would appreciate it if you could take a look when you
have a moment.

Thanks for your time,
Yuqi

On Fri, Sep 18, 2026 at 07:56:53 +0200, Mika Westerberg wrote:
> On Fri, Sep 18, 2026 at 01:41:09PM +0800, Yuqi Xu wrote:
> > The ELAN0662 touchpad (04F3:317C) in the Lenovo ThinkBook 14 G4+ ARA
> > (21D0) intermittently stutters and drops touches. libinput discards
> > invalid touch coordinates and logs (rate limited to five messages per
> > 24 hours):
> >
> >   libinput error: event6 - ELAN0662:00 04F3:317C Touchpad: kernel
> >   bug: Touch jump detected and discarded.
> >
> > The ACPI DSDT describes the touchpad's I2cSerialBus resource on an
> > AMDI0010 controller with a connection speed of 0x00061A80 (400 kHz),
> > and the kernel does not lower it for this device, so the touchpad runs
> > at 400 kHz. This is the same issue previously fixed for ELAN06FA and
> > ELAN0678.
> >
> > Forcing the bus to 100 kHz was tested with a DSDT override on the
> > affected machine, and the kernel confirmed the override:
> >
> >   ACPI: Table Upgrade: override [DSDT-LENOVO-CB-01]
> >
> > Before the change libinput discarded three touch jumps within about a
> > minute of touchpad use; after the change no touch jumps were logged
> > during more than an hour of normal use. The patch itself was not build
> > tested; the behaviour was validated through the ACPI table override
> > above.
> >
> > Assisted-by: DeepSeek:deepseek-v4.1-flash
> > Signed-off-by: Yuqi Xu <xuyuqiabc@xxxxxxxxx>
>
> Acked-by: Mika Westerberg (Intel) <westeri@xxxxxxxxxx>