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

Mika Westerberg
2025-01-10T12:07:43Z

On Fri, Jan 10, 2025 at 01:45:03PM +0200, Jarkko Nikula wrote:
> On 1/10/25 1:26 PM, Mika Westerberg wrote:
> > 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.
>
> Unfortunately I don't have idea.

Okay thanks anyway! Then I don't see any other option than adding that
quirk.

@R Ha, can you then submit a new version of the patch with the latest
details in the changelog?