Re: Dell Vostro V131 hotkeys revisited

[Darren Hart <dvhart@infradead.org>]

On Mon, Aug 31, 2015 at 11:51:07AM +0200, Michał Kępień wrote:
> > > > Now as for actually simulating a keypress, it can be programmed using
> > > > the following calling interface (on receiving the e025 WMI notification).
> > > > To actually simulate the keypress:
> > > > Arg1=0x41
> > > > Arg2 Byte [1:0]: Scan code to simulate
> > > > Byte [3:2]
> > > > * Bit0 - L Alt
> > > > * Bit1 - R Alt
> > > > * Bit2 - L Ctrl
> > > > * Bit3 - R Ctrl
> > > > * Bit4 - L Shift
> > > > * Bit5 - R shift
> > > > * Bit6 - L Win
> > > > * Bit7 - R Win
> > > > * Bit8 - Fn key
> > > 
> > > And is it possible to disable keypress simulation on systems that have
> > > that capability?
> > > 
> > > My understanding is that all hardware equipped with an Instant Launch
> > > button is capable of generating a WMI event upon its press, but not all
> > > models can generate a keypress at the same time, correct? If that's the
> > > case, then the arguably cleanest solution would be to change the keymap
> > > entry for event 0xe025 in dell-wmi.c to KE_KEY and ensure (probably in
> > > dell-laptop.c) no i8042 interrupt is raised when the Instant Launch
> > > button is pressed. Though that would still leave us with the question of
> > > how to determine (ideally without side effects) whether a given model
> > > needs disabling keypress simulation. I imagine the pseudocode would be
> > > like:
> > > 
> > >     if (ec_can_simulate_keypresses)
> > >         disable_keypress_simulation();
> > >     else
> > >         enable_wmi_event_generation();
> > > 
> > > If disabling keypress simulation is not possible, dell-wmi.c has to
> > > somehow determine whether a 0xe025 WMI event should be ignored or not.
> > > 
> > > Am I making any sense here?
> 
> As the holiday season is coming to an end, I'm taking my last shot at
> reviving this thread. Could anyone please tell us:
> 
>   * Is there a way to determine whether the EC is capable of simulating
>     keypresses without the side effects that the SMBIOS call 4, 11 with
>     argument 64 causes on certain hardware (e.g. disabling keyboard
>     backlight on an E6440)? Or is there perhaps a well-defined list of
>     machines that SMBIOS call is (un)safe on?
> 
>   * Is it possible to disable keypress simulation on machines on which
>     the EC supports it? If so, how would one do that?

I certainly don't know myself, not what you were hoping to hear back I'm sure.
Some of that requires documentation, which I don't know if we have. Does anyone
from Dell on Cc have documentation they can share to help answer these
questions?

-- 
Darren Hart
Intel Open Source Technology Center