[PATCH] i2c: acpi: Force ASUE140D touchpads to 100 kHz

[PATCH] i2c: acpi: Force ASUE140D touchpads to 100 kHz

[Harinn via B4 Relay]

From: Harinn <prinn.dev@pm.me>

The ASUE140D touchpad on the ASUS Zenbook UX3404VC (BIOS UX3404VC.303)
starts lagging shortly after boot when the bus runs at the 400 kHz the
DSDT asks for, and only recovers after rebinding i2c-hid. Forcing
100 kHz fixes it.

Signed-off-by: Harinn <prinn.dev@pm.me>
---
 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 8f3bdd50186e..e5b27375af31 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -371,6 +371,7 @@ static const struct acpi_device_id i2c_acpi_force_100khz_device_ids[] = {
 	 * the device works without issues on Windows at what is expected to be
 	 * a 400KHz frequency. The root cause of the issue is not known.
 	 */
+	{ "ASUE140D", 0 },
 	{ "DLL0945", 0 },
 	{ "ELAN0678", 0 },
 	{ "ELAN06FA", 0 },

---
base-commit: 6addb4f385570ebc11c4eb499a4f1c149f313e84
change-id: 20261004-i2c-acpi-asue140d-100khz-44764ecff725

Best regards,
--  
Harinn <prinn.dev@pm.me>

Re: [PATCH] i2c: acpi: Force ASUE140D touchpads to 100 kHz

[Mika Westerberg]

On Sun, Oct 04, 2026 at 05:59:53PM +0700, Harinn via B4 Relay wrote:
> From: Harinn <prinn.dev@pm.me>
> 
> The ASUE140D touchpad on the ASUS Zenbook UX3404VC (BIOS UX3404VC.303)
> starts lagging shortly after boot when the bus runs at the 400 kHz the
> DSDT asks for, and only recovers after rebinding i2c-hid. Forcing
> 100 kHz fixes it.
> 
> Signed-off-by: Harinn <prinn.dev@pm.me>

Acked-by: Mika Westerberg <westeri@kernel.org>

Re: [PATCH] i2c: acpi: Force ASUE140D touchpads to 100 kHz

[Andi Shyti]

Hi Harinn,

next time, please...

On Sun, Oct 04, 2026 at 05:59:53PM +0700, Harinn via B4 Relay wrote:
> From: Harinn <prinn.dev@pm.me>
> 
> The ASUE140D touchpad on the ASUS Zenbook UX3404VC (BIOS UX3404VC.303)
> starts lagging shortly after boot when the bus runs at the 400 kHz the
> DSDT asks for, and only recovers after rebinding i2c-hid. Forcing
> 100 kHz fixes it.
> 
> Signed-off-by: Harinn <prinn.dev@pm.me>

... try to use your full name and ...

> ---
>  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 8f3bdd50186e..e5b27375af31 100644
> --- a/drivers/i2c/i2c-core-acpi.c
> +++ b/drivers/i2c/i2c-core-acpi.c
> @@ -371,6 +371,7 @@ static const struct acpi_device_id i2c_acpi_force_100khz_device_ids[] = {
>  	 * the device works without issues on Windows at what is expected to be
>  	 * a 400KHz frequency. The root cause of the issue is not known.
>  	 */
> +	{ "ASUE140D", 0 },

... develop your patches on top of the -next branch or i2c/i2c.
Your patch has a little conflict I had to fix.

I pushed your patch in i2c/i2c.

Thanks,
Andi

>  	{ "DLL0945", 0 },
>  	{ "ELAN0678", 0 },
>  	{ "ELAN06FA", 0 },

Re: [PATCH] i2c: acpi: Force ASUE140D touchpads to 100 kHz

[James Heppell]

I've been experiencing a similar issue to this on an Asus Zenbook Flip
UP3404VA with the same ASUE140D touchpad. The touchpad goes unresponsive
until I rebind the driver or restart, and I most frequently experience
this after exiting tablet mode. I reported this to the KDE bug tracker
here https://bugs.kde.org/show_bug.cgi?id=480671 at first before
realising it was a kernel issue.

I've built Fedora's 7.2.10 kernel with this patch on my Zenbook and it
seems to have fixed the issue for me as well. Thanks for looking into
it. It would be great if the patch could be backported to stable kernels
by adding Cc: stable@vger.kernel.org.

Tested-by: James Heppell <formularsumo@outlook.com>

Thanks,
James Heppell