[PATCH] i2c: Force DLL0945 touchpad i2c freq to 100khz

[PATCH] i2c: Force DLL0945 touchpad i2c freq to 100khz

[fangzhong.zhou]

Signed-off-by: fangzhong.zhou <myth5@myth5.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 d2499f302b50..5b424637bbaf 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[] = {
 	 * a 400KHz frequency. The root cause of the issue is not known.
 	 */
 	{ "ELAN06FA", 0 },
+	{ "DLL0945", 0 },
 	{}
 };
2.48.1

Re: [PATCH] i2c: Force DLL0945 touchpad i2c freq to 100khz

[Wolfram Sang]

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On Fri, Jun 20, 2025 at 01:28:31PM +0800, fangzhong.zhou wrote:
> Signed-off-by: fangzhong.zhou <myth5@myth5.com>

Please add a commit message indicating on which laptop you encountered
the issue, what happened before and after the fix.


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Re: [PATCH] i2c: Force DLL0945 touchpad i2c freq to 100khz

[fangzhong.zhou]

On Mon, Jul 28, 2025 at 10:59 AM +0200, Wolfram Sang wrote:
>Please add a commit message indicating on which laptop you encountered
>the issue, what happened before and after the fix.

Ok, thanks for tell me. This issue happened in the dell precision 5560.
When the issue happens, the cursor movements become shorter, 
meaning that to the same input swipe, the traveled distance of the 
cursor is like half of the expected one.
It's also really hard to make precise movements. But if apply this 
patch, the touchpad still work well and have expected precise movements

[PATCH v1] i2c: Force DLL0945 touchpad i2c freq to 100khz

[fangzhong.zhou]

This patch fixes an issue where the touchpad cursor movement becomes
slow on the Dell Precision 5560. Force the touchpad freq to 100khz
as a workaround.

Tested on Dell Precision 5560 with 6.14 to 6.14.6. Cursor movement
is now smooth and responsive.

Changes in v1:
	- No code changes from first commit.

Signed-off-by: fangzhong.zhou <myth5@myth5.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 d2499f302..5b424637b 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[] = {
 	 * a 400KHz frequency. The root cause of the issue is not known.
 	 */
 	{ "ELAN06FA", 0 },
+	{ "DLL0945", 0 },
 	{}
 };
 
-- 
2.48.1

Re: [PATCH v1] i2c: Force DLL0945 touchpad i2c freq to 100khz

[Wolfram Sang]

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On Sun, Aug 03, 2025 at 07:15:54AM +0800, fangzhong.zhou wrote:
> This patch fixes an issue where the touchpad cursor movement becomes
> slow on the Dell Precision 5560. Force the touchpad freq to 100khz
> as a workaround.
> 
> Tested on Dell Precision 5560 with 6.14 to 6.14.6. Cursor movement
> is now smooth and responsive.
> 
> Changes in v1:
> 	- No code changes from first commit.

The "Changes" section should go below "---". I fixed it.

> 
> Signed-off-by: fangzhong.zhou <myth5@myth5.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 d2499f302..5b424637b 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[] = {
>  	 * a 400KHz frequency. The root cause of the issue is not known.
>  	 */
>  	{ "ELAN06FA", 0 },
> +	{ "DLL0945", 0 },

I moved it up to keep alphabetical sorting.

With these changes:

Applied to for-next (for 6.17 mergewindow), thanks!


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