cursor handling and updates inside DRM

[Tiago Vignatti]

Stephane Marchesin escreveu:
> On Fri, Jul 11, 2008 at 1:12 AM, Tiago Vignatti <vignatti at c3sl.ufpr.br> wrote:
>> Yeah, but the current design in the kms (i.e. DRM touching the
>> registers) is not good as well. The pointer is jumping a lot -- much
>> more than the "old" design -- because with a single device movement it
>> emits a hundred of events and a lot of context switch is done. Not cool.
>>
> 
> Care to elaborate ? What you describe here sounds like an
> implementation-specific issue, more than an issue with KMS.

Okay, I lied here ;) The reason of the cursor jumping is not the number 
of context switches. Dave helped me to identify the real reason.

Try to call a xrandr instance and move the mouse with kernel 
modesetting. xrandr will do DDC communication which will blocked X in 
the kernel. With my implementation of the X server using a separate 
thread to take care the input events this is _reduced_ because signals 
is not used to wake up the devices.

Moreover, with the handling and update of the cursor inside the kernel 
all would work perfectly smooth (in fact I tried it with my 
proof-of-concept and it was confirmed).


Thanks you,

-- 
Tiago Vignatti
C3SL - Centro de Computação Científica e Software Livre
www.c3sl.ufpr.br