* [PATCH] i2c: acpi: Add ELAN0678 to i2c_acpi_force_100khz_device_ids
@ 2026-04-18 5:37 Niels Franke
2026-04-20 8:37 ` Mika Westerberg
0 siblings, 1 reply; 2+ messages in thread
From: Niels Franke @ 2026-04-18 5:37 UTC (permalink / raw)
To: westeri; +Cc: wsa+renesas, linux-i2c, linux-acpi, linux-kernel, Niels Franke
The ELAN0678 touchpad (04F3:3195) found in the Lenovo ThinkPad X13
exhibits excessive smoothing when the I2C bus runs at 400KHz, making
the touchpad feel sluggish when plugged into AC power. This is the
same issue previously fixed for ELAN06FA.
The device's ACPI table (Lenovo TP-R22) specifies 0x00061A80 (400KHz)
for the I2cSerialBusV2 descriptor. Forcing the bus to 100KHz eliminates
the sluggish behavior.
Signed-off-by: Niels Franke <nielsfranke@gmail.com>
---
drivers/i2c/i2c-core-acpi.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 2cbd31f77..96d339df0 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -372,6 +372,7 @@ static const struct acpi_device_id i2c_acpi_force_100khz_device_ids[] = {
*/
{ "DLL0945", 0 },
{ "ELAN06FA", 0 },
+ { "ELAN0678", 0 },
{}
};
--
2.53.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] i2c: acpi: Add ELAN0678 to i2c_acpi_force_100khz_device_ids
2026-04-18 5:37 [PATCH] i2c: acpi: Add ELAN0678 to i2c_acpi_force_100khz_device_ids Niels Franke
@ 2026-04-20 8:37 ` Mika Westerberg
0 siblings, 0 replies; 2+ messages in thread
From: Mika Westerberg @ 2026-04-20 8:37 UTC (permalink / raw)
To: Niels Franke; +Cc: westeri, wsa+renesas, linux-i2c, linux-acpi, linux-kernel
On Sat, Apr 18, 2026 at 07:37:19AM +0200, Niels Franke wrote:
> The ELAN0678 touchpad (04F3:3195) found in the Lenovo ThinkPad X13
> exhibits excessive smoothing when the I2C bus runs at 400KHz, making
> the touchpad feel sluggish when plugged into AC power. This is the
> same issue previously fixed for ELAN06FA.
>
> The device's ACPI table (Lenovo TP-R22) specifies 0x00061A80 (400KHz)
> for the I2cSerialBusV2 descriptor. Forcing the bus to 100KHz eliminates
> the sluggish behavior.
>
> Signed-off-by: Niels Franke <nielsfranke@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2026-04-18 5:37 [PATCH] i2c: acpi: Add ELAN0678 to i2c_acpi_force_100khz_device_ids Niels Franke
2026-04-20 8:37 ` Mika Westerberg
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