Re: [PATCH] HID: multitouch: add a quirk to skip set inputmode for 2 new laptops

["Barnabás Pőcze" <pobrn@protonmail.com>]

Hi


2021. január 7., csütörtök 12:27 keltezéssel, Hui Wang írta:

> we have 2 latest Thinkpad laptops, the synaptics trackpoint module is
> connected to i8042 bus and the synaptics touchpad module is on the i2c
> bus. The trackpoint is driven by input/mouse/trackpoint.c and the
> touchpad is driven by hid-multitouch.c.
>
> They all work well independently, but if users press any buttons of
> trackpoint and meanwhile move finger on the touchpad, the touchpad
> can't work, the i2c bus can't generate interrupts even. That is to say
> the touchpad can't work with trackpoint together, once trackpoint
> works, the touchpad stops working.
>
> The current hid driver parses the device descriptor and selects the
> hid-multitouch.c and applies the MT_CLS_WIN_8 to the touchpad, I found
> this issue begins to happen after the driver sets the
> MT_INPUTMODE_TOUCHPAD to the device, If skipping to set it, the
> touchpad work well and doesn't have that issue, even after suspend and
> resume, the touchpad still work well.
>
> This touchpad module doesn't support multi inputmodes, and its init
> mode is set by BIOS already, it is safe to skip to set it again in
> the kernel driver.
> [...]

Assuming I'm not missing anything obvious, a windows precision touchpad
should revert back to reporting events via its HID compliant mouse collection
when power cycled or reset by the host[1].

Doesn't that imply that the events will be reported via the mouse collection
in this case, and that the multi-touch capabilities of the device will not
be usable? Or am I missing something?


[1]: https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/windows-precision-touchpad-required-hid-top-level-collections#input-mode-feature-report


Regards,
Barnabás Pőcze