Re: Dell Vostro V131 hotkeys revisited

["Pali Rohár" <pali.rohar@gmail.com>]

On Friday 03 July 2015 13:26:11 Michał Kępień wrote:
> > It looks like above buffer has format of *new* event (0002 - length of
> > event, 0000 - type of event, e025 - data). But when using legacy keymap
> > then dell-wmi.c parse events with old format (which means type=0000 is
> > dropped and data=e025 is translated to some key).
> > 
> > This is even harder as I thought. Looks like big mess and now I would
> > say, without documentation for Dell WMI events we are not able to fix
> > this correctly without breaking other laptops...
> 
> As far as I understand, the specific case that we're dealing with here
> is that on one laptop model a certain WMI event is generated along with
> a keycode while another mothel generates the same WMI event without an
> accompanying keycode. Currently the Dell WMI driver ignores the WMI
> event in question, but it is processed by i8042.
> 
> Could we perhaps do the opposite for this specific event, i.e. filter it
> out using the i8042 filter in dell-laptop.c and translate the WMI event
> into a keycode in dell-wmi.c? This shouldn't conflict with the dell-rbtn
> driver as there are no ACPI devices on an XPS L502X that could be
> handled by that driver [1] and thus the i8042 filter should be
> installed. However, that i8042 keycode could potentially be generated on
> other, WMI-less models and such a change would break them, rendering it
> unacceptable. I also assumed pressing the hotkey in question on an XPS
> L502X produces the same i8042 keycode as the WMI event code indicates...
> 
> [1] this statement is based on the DSDT dump from a Dell XPS L502X that
>     I found here: https://launchpadlibrarian.net/68880655/DSDT.dsl
> 

I would like to wait for documentation and not to invent/mess something
again and more. Creating big list with DMI names and associate hooks for
them based on "our" observation is good way to hell!

We even do not know:

1) how to activate code for receiving events
2) what is format of which event
3) which keypress should be reported by i8042 bus and which via ACPI/WMI

-- 
Pali Rohár
pali.rohar@gmail.com