Re: Logitech Spring FF

[Richard Bolkey <rbolkey@cs.utexas.edu>]

First off, I've never made a patch before, which I guess I better learn, 
but for now if anyone wants to add the device_type for the Logitech 
Force 3D Pro Joystick to hid-lgff.c, it's { 0x046d, 0xc286, ff_joystick }.

Now for a few follow up questions (this is a whole lot of new stuff, so 
bear with me).

1) I'm gathering that Logitech keeps their hid reports secret and 
non-standard, or else I'd just be using the HID PID driver?  So, were 
the values in the reports found in hid_lgff_play discovered through 
trial and error?  How would I find what the report for FF_SPRING should 
look like?

2) Previous question assumes that is where I should implement the effect 
since ml->play_effect is referencing that function in ff_memless.c.  But 
it sounded like Anssi was recommending doing a spring->constant 
conversion akin to what looks like a periodic->rumble conversion in 
ml_combine_effects?

Thanks,
Rick