Hi Eray,
On 11/10/22 19:47, Eray Orçunus wrote:
> Hi,
>
> On 10 Nov 2022 at 21:09, Maxim Mikityanskiy <maxtram95@xxxxxxxxx> wrote:
>> A small note on the DMI allow-list: I don't think Z570 is the only
>> laptop where EC fails to disable the touchpad. While I would like this
>> hack to affect as few laptops as possible, I would expect that other
>> similar models produced in the same time period suffer from the same
>> issue, and I don't think we have the full list of them.
>
> I just checked Z570 ACPI table, and this is what it does when it receives
> VPCCMD_R_TOUCHPAD:
>
> VDAT = TPEN /* \_SB_.PCI0.LPCB.EC0_.TPEN */
> If ((TPEN == One))
> {
> GL04 |= 0x02
> }
> Else
> {
> GL04 &= 0xFD
> }
>
> VDAT is the data returned to user.
> So we can say that TPEN is the logical state of touchpad key, and GL04
> is state of touchpad LED or series of LEDs.
>
> VPCCMD_W_TOUCHPAD is nulled, it doesn't work.
>
> I also checked which DSDTs I have (13 DSDTs from 2008 to this year)
> contain TPEN, and turned out it was only S12, from 2009. It also had
> nulled VPCCMD_W_TOUCHPAD, and returns TPEN on VPCCMD_R_TOUCHPAD, except
> it doesn't have an LED or GL04.
>
> So, it's possible that we can only check if TPEN exists on ACPI table,
> instead of having a white-list.
Hmm, lets keep that idea in case it turns out the allow-list based
approach turns out to cause issue/grow out of control. I would rather
not rely on ACPI variables having a specific name for something like
this, but you might be on to something.
I have checked my own collection of acpidumps and the only DSDT
which I have which has a TPEN variable is for an Ideapad D330.
Funny enough that is a 2-in-1 with a detachable USB keyboard.
I would not be surprised if the ideapad driver does not load
on those devices at all since there are no embedded-controller
handled hotkeys, as the keyboard is fully USB/HID and not
connected to the EC at all.
I'll send you the acpidump in a private email.
Regards,
Hans
