Re: [PATCH] HID: i2c-hid: override HID descriptors for some Haptick 5288 touchpads

[kenkinming2002@gmail.com]

On Thu, Jan 08, 2026 at 02:14:29AM +0800, kenkinming2002@gmail.com wrote:
> > The simplest "solution" following what you are doing is making a HID-BPF
> > fixup which checks whether the device properly sent the report
> > descriptor and if not puts the one here. The HID-BPF has the advantage
> > of being compatible with hid-multitouch so you won't get into troubles
> > with a separate module.
> This might be a solution but would that not only fix it just for me? I
> would have to look into how to do HID-BPF fixup.
An update, I have looked into HID-BPF but it seems to me that we can
only fix up the HID report descriptor and not the HID descriptor (this
descriptor is specific to i2c-hid device) but from my testing both
descriptor can be corrupted. Specifically, I see messages such as:

  i2c_hid_acpi i2c-SPPT2600:00: unexpected HID descriptor bcdVersion (0x0209)
  i2c_hid_acpi i2c-SPPT2600:00: Failed to fetch the HID Descriptor

appearing in my log.

For now, I am just going to just apply the patch locally for myself till
a better solution come up.

I have finally clean up the pile of garbage I have while investigating
the problem and put up a proper git repository with relevant script and
logs at https://github.com/kenkinming2002/samsung-i2c-hid-bug-repro.git.

Huge thanks to Benjamin and anyway who might have stumbled across this
patch for your time.

Yours sincerly,
Ken Kwok