Re: [PATCH] i2c: acpi: Add ELAN0678 to i2c_acpi_force_100khz_device_ids

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi,

On Tue, May 12, 2026 at 11:36:26PM +0200, Odoben wrote:
> Hi,
> 
> I have what appears to be the same issue on a ThinkPad X13 Gen 2 with
> Intel i5-1145G7, but with ACPI HID ELAN0676 instead of ELAN0678.
> 
> The touchpad is:
> 
> ELAN0676:00 04F3:3195 Touchpad
> 
> libinput reports:
> 
> Id: i2c:04f3:3195
> 
> dmesg shows:
> 
> i2c_designware.0 -> i2c-ELAN0676:00 -> hid-multitouch
> 
> The ACPI table contains:
> 
> Package (0x06)
> {
> 0x04F3,
> 0x3195,
> 0x15,
> One,
> One,
> "ELAN0676"
> }
> 
> and the surrounding firmware logic maps the fifth field to speed:
> 
> Local5 == Zero -> SPED = 0x000186A0 = 100 kHz
> Local5 == One -> SPED = 0x00061A80 = 400 kHz
> 
> So this machine also configures the 04F3:3195 ELAN touchpad at 400 kHz. The
> symptom is very frequent rubbery/sluggish pointer movement, consistent with
> the excessive smoothing described for ELAN0678.
> 
> Would it make sense to include ELAN0676 in the
> same i2c_acpi_force_100khz_device_ids quirk?

Did you try 100Hz and it made the problem go away? In that case yes it
makes sense to add the quirk.