Re: [PATCH v4 01/24] input: Add ff-memless-next module

[Elias Vanderstuyft <elias.vds@gmail.com>]

On Tue, May 20, 2014 at 10:58 PM, Michal Malý
<madcatxster@devoid-pointer.net> wrote:
> On Tuesday 20 of May 2014 16:16:12 simon@mungewell.org wrote:
>> Regarding the question of emulated vs. real effects, can we extend the API
>> so that applications can know which effects are really supported, and
>> enable/disable emulation somehow?
>
> I suppose that a few extra flags (FF_PERIODIC_EMULATED etc.) defined in
> "uapi/linux/input.h" should suffice.

@Dmitry:
Now that we're talking about API changes, I would like to propose some
additional things in the Linux FF API:

- Possibility to *get* FF state variables, such as the value of the
current GAIN, and the current AUTOCENTER:
At the moment, only *setting* is possible.
This poses a problem when implementing proper AUTOCENTER state
recovery (upon closing a Windows program) in Wine, because the initial
AUTOCENTER state was unknown.
The same applies for GAIN.

- Introduce multiple types of GAIN, apart from the current global
GAIN, e.g. GAIN_CONSTANT and GAIN_DAMPER:
This is mainly on request of some users, especially Logitech users: on
Windows Logitech additionally supports to set the global Damper and
Spring gain.
Maybe it would be nicer to create a global gain for every supported
Linux FF effect?

Thanks,
Elias