Re: [PATCH 1/2] platform/x86: asus-wmi: Call new led hw_changed API on kbd brightness change

[Hans de Goede]

Hi,

On 05-06-18 12:46, Benjamin Berg wrote:
> Hey,
>
> On Tue, 2018-06-05 at 12:31 +0200, Hans de Goede wrote:
> > On 05-06-18 12:14, Bastien Nocera wrote:
> > > On Tue, 2018-06-05 at 12:05 +0200, Hans de Goede wrote:
> > > > On 05-06-18 11:58, Bastien Nocera wrote:
> > > > > [SNIP]
> > > >
> > > > Ok, so what are you suggestion, do you really want to hardcode
> > > > the cycle behavior in the kernel as these 2 patches are doing,
> > > > without any option to intervene from userspace?
> > > >
> > > > As mentioned before in the thread there are several example
> > > > of the kernel deciding to handle key-presses itself, putting
> > > > policy in the kernel and they have all ended poorly (think
> > > > e.g. rfkill, acpi-video dealing with LC brightnesskey presses
> > > > itself).
> > > >
> > > > I guess one thing we could do here is code out both solutions,
> > > > have a module option which controls if we:
> > > >
> > > > 1) Handle this in the kernel as these patches do
> > > > 2) Or send a new KEY_KBDILLUMCYCLE event
> > > >
> > > > Combined with a Kconfig option to select which is the default
> > > > behavior. Then Endless can select 1 for now and then in
> > > > Fedora (which defaults to Wayland now) we could default to
> > > > 2. once all the code for handling 2 is in place.
> > > >
> > > > This is ugly (on the kernel side) but it might be the best
> > > > compromise we can do.
> > >
> > > I don't really mind which option is used, I'm listing the problems with
> > > the different options. If you don't care about Xorg, then definitely go
> > > for adding a new key. Otherwise, processing it in the kernel is the
> > > least ugly, especially given that the key goes through the same driver
> > > that controls the brightness anyway. There's no crazy cross driver
> > > interaction as there was in the other cases you listed.
> >
> > Unfortunately not caring about Xorg is not really an option.
> >
> > Ok, new idea, how about we make g-s-d behavior upon detecting a
> > KEY_KBDILLUMTOGGLE event configurable, if we're on a Mac do a
> > toggle, otherwise do a cycle.
> >
> > Or we could do this through hwdb, then we could add a hwdb entry
> > for this laptop setting the udev property to do a cycle instead of
> > a toggle on receiving the keypress.
>
> If we are adding hwdb entries anyway to control the userspace
> interpretation of the TOGGLE key, then we could also add the new CYCLE
> key and explicitly re-map it to TOGGLE. That requires slightly more
> logic in hwdb, but it does mean that we could theoretically just drop
> the workaround if we ever stop caring about Xorg.

Hmm, interesting proposal, I say go for it :)

Regards,

Hans