Re: [PATCH 1/1] Force ELAN06FA touchpad I2C bus freq to 100KHz

Mika Westerberg
2025-01-10T11:26:26Z

Hi,

On Fri, Jan 10, 2025 at 02:31:26AM -0600, R Ha wrote:
> Hi,
>
> Sounds like a good idea. I'm a little worried I'm missing something,
> so I think being able to check my earlier answers will help as well.
> I'm sending the entire output as attachments, but let me know if it's
> better to upload them somewhere and paste the link instead. Some of
> the ssdt* files are missing, but they're empty files so Gmail won't
> let me attach them.

Thanks for sharing! Okay checked now dsdt.dsl (the other files are not
relevant here) and what I can tell the device is supposed to be run at 400
kHz. I suspect this is what Windows is doing as well, there is nothing that
indicates otherwise.

And since this is a standard I2C HID device it should just work (as it does
not require any vendor specific driver even in Windows).

Only thing I can think of that affects this is the LCNT/HCNT and SDA hold
values of the I2C designware controller (and maybe the input clock) but
there is nothing in the ACPI tables that set these so it could be that the
Windows driver uses different values for those and that explains why it
works better there.

@Jarkko, do you have any input here? If we cannot figure a better way then
I don't see other option than to add this quirk.